Michaels v. Pentair Water Pool & Spa , 2015 NV 81 ( 2015 )


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  •                                                          131 Nev., Advance Opinion• 8
    IN THE COURT OF APPEALS OF THE STATE OF NEVADA
    EMMETT J. MICHAELS,                                   No. 59685
    Appellant,
    vs.
    PENTAIR WATER POOL AND SPA,                                      FILED
    INC., A DELAWARE CORPORATION,
    Respondent.                                                       OCT 0 1 2015
    LAE K. LINDEMAN
    CL                        RI
    CHIEF DEP4T\ CLER
    Appeal from a final district court order in a products thibility
    action. Eighth Judicial District Court, Clark County; Douglas W.
    Herndon, Judge.
    Vacated and remanded.
    Winner & Carson, P.C., and Robert A. Winner and Brent A. Carson, Las
    Vegas,
    for Appellant.
    Lewis Roca Rothgerber LLP and Daniel F. PoIsenberg and Joel D.
    Henriod, Las Vegas; Buchalter Nemer and George J. Stephan, Los
    Angeles, California,
    for Respondent.
    BEFORE GIBBONS, C.J., TAO and SILVER, JJ.
    OPINION
    By the Court, TAO, J.:
    The instant appeal arises from allegations of attorney
    misconduct in a products liability trial involving swimming pool filters.
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    After the jury rendered a verdict in favor of the manufacturer, the plaintiff
    filed a post-trial motion seeking a new trial based upon alleged misconduct
    committed by the manufacturer's attorney. The district court denied the
    motion, but failed to make the detailed findings required by the Nevada
    Supreme Court.
    The Nevada Supreme Court recently issued two opinions
    clarifying how claims of attorney misconduct must be handled both by the
    district court and subsequently on appeal. In this opinion, we take the
    opportunity to summarize those recent developments and to provide
    guidance to district courts tasked with resolving claims of misconduct.
    Because the district court in this case failed to make detailed findings
    regarding the alleged misconduct that might have enabled us to determine
    whether those cases would have affected its decision, we must remand the
    case to the district court to reconsider its decision in light of those cases
    and to make the necessary findings. To assist the district court, we
    identify some factors that must be considered on remand.
    FACTS
    Respondent Pentair Water Pool and Spa, Inc. (Pentair),
    manufactures various models of swimming pool filters for both commercial
    and residential swimming pools, including the Nautilus FNS filter. In
    2006, appellant Emmett Michaels purchased a Nautilus FNS filter for use
    in his backyard swimming pool. Michaels had owned his swimming pool
    for 27 years, and when his previous filter canister malfunctioned, he
    integrated the FNS canister into his preexisting filter system. Like many
    other homeowners, Michaels connected his pool filter system to an
    automatic timer that could be programmed to turn the system off at night
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    and on again during the day.' On July 1, 2008, the filter system was
    turned off but Michaels manually turned it on in anticipation of guests
    arriving The FNS filter canister exploded, and pieces struck Michaels in
    the left eye and ruptured his eyeball, which had to be removed and
    replaced with a prosthesis. 2 Thereafter, Michaels initiated the underlying
    action and sought damages based on his injuries. While Michaels asserted
    several claims for relief, only the products liability claim is the subject of
    the instant appeal.
    Michaels alleged that the design of the FNS filter was legally
    defective because it lacked either (1) a redundant or secondary restraint to
    hold the canister together in the event of an explosive failure of the clamp;
    or (2) an external, automatic air release valve allowing any compressed air
    trapped within the canister to be released if pressure reached dangerous
    levels. Michaels also alleged that Pentair failed to give him proper
    warnings regarding the risk of explosion.
    Following a two-week trial, the jury returned a verdict in favor
    of Pentair on all claims. Michaels filed a post-trial motion for judgment as
    a matter of law or, alternatively, for a new trial, which was denied by the
    district court. Michaels now appeals from the denial of that motion.
    1 During the trial, witness testimony was presented that "almost all"
    homeowners connect their filter systems to automatic timers, an assertion
    that was not disputed by Pentair.
    2 While,as discussed below, some of the precise circumstances
    surrounding Michaels' eye injury were disputed below and are again
    disputed on appeal, that the filter canister exploded and that the explosion
    was the proximate cause of the injury to Michaels' eye appears to be
    undisputed.
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    The operation of swimming pool filters
    In order to properly understand the evidence and the
    arguments made by the parties, a brief explanation of the operation of
    swimming pool filters is appropriate. The Nautilus FNS filter is a so-
    called split-shell design consisting of two pieces held together by a steel
    clamp to form a cylinder in which removable filter grids are placed. In
    operation, water is pumped from the pool and forced under pressure
    through the filter grids, which trap debris and remove it from the pool
    water. The steel clamp that holds the two cylinder pieces together can be
    removed so that the canister may be separated and the filter grids
    periodically cleaned or replaced.
    Pool filter systems are designed as either open systems, in
    which a water pump pushes pool water through the filter, or closed
    systems, in which a water pump suctions water through the filter. In
    either system, a system of pipes carries water from the pool through the
    filter canister and then back to the pool. The flow of water through the
    system may be directed by a series of valves mounted on the pipes.
    After a filter has been in operation for some time, debris from
    the pool can accumulate on the filter grids and eventually may clog the
    flow of water through the system, impeding the effectiveness of the
    system. To allow removal of some of the debris, some users manipulate
    the valves to reverse the flow of water through the filter grids and into a
    separation tank that collects the debris, in a process colloquially known as
    backwashing. Pentair discourages backwashing and its engineers
    consider it unsafe, but during trial its expert conceded that manufacturers
    were aware that users frequently backwashed filters and that such
    backwashing was foreseeable. In any event, after the filter grids have
    been backwashed, the valves can be switched back to their normal
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    operating positions. Even with regular backwashing, however, the filter
    grid elements can eventually become so clogged with detritus that they
    may sometimes have to be removed and replaced entirely, which is why
    split-shell filter canisters such as the Nautilus FNS are designed with
    clamps allowing the canister to be opened.
    So long as the filter system is operating normally, water
    continually moves through the filter cartridge and the water pressure
    within the filter canister remains more or less constant. However, the
    pressure within the system may vary from its normal operating levels
    under two conditions. First, if a large quantity of debris has collected on
    the filter grids and clogged the system, a water pressure differential may
    be created within the system as water is pumped into the filter canister
    under pressure but only trickles out through the clogged grids. This is not
    normally considered a dangerous occurrence, because water (unlike air)
    cannot be easily compressed and most filter systems can safely contain
    water pressure differentials without difficulty, although the ability of
    those systems to clean the water may become compromised.
    Far more relevant to the instant case is the second condition,
    which may occur when the filtration system is turned completely off,
    causing the water to stop flowing and potentially permitting air to bleed
    into the system. In commercial pool systems, this condition rarely occurs
    because most commercial pools are left on continuously, except perhaps
    occasionally when being actively serviced. On the other hand, many
    residential pool systems are regularly turned on and off by homeowners
    (usually at night or during the winter months when the pool is rarely
    used) in order to save electricity. Indeed, testimony was presented that
    the majority of residential pool owners connect their pool filter systems to
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    timers that automatically turn the system off at night and back on during
    the day.
    When the system is turned off and then turned back on, air
    that bled into the system while it was off is pushed into the canister by the
    flow of water. If the filter grids are clogged, the air may become trapped
    within the canister against the clog with nowhere to go. As more air and
    water continue to be pumped into the canister under pressure, air
    pressure may build up within the canister, creating a condition known in
    the industry as a dead-head. If the pressurized air cannot find a way to
    escape, the air pressure within the canister grows to dangerous levels as
    more air and water are forced into the system. When the air pressure
    within the canister exceeds the ability of the metal clamp to hold the
    canister together, the canister may explode. 3
    To reduce the risk of such explosive dead-heads, the
    instruction manual accompanying the FNS filter "recommends" that the
    consumer manually bleed excess air from the system each and every time
    the system is turned off and on. However, when a pool filter is connected
    to a timer that automatically turns the system off at night and on during
    the day with no action by the homeowner, the recommendations contained
    in the instruction manual cannot be complied with, because an automated
    timer system will not manually bleed out air every time the filter is cycled
    back on.
    3 Some   filter canisters are sold as single piece or single tank
    canisters that cannot be opened, and the filter grids in those types of
    canisters cannot be replaced or removed for cleaning. Based upon
    testimony at trial, no explosions of single piece canisters are known to
    have occurred.
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    The evidence and arguments at trial
    Michaels contended that the known risks of explosion
    rendered the design of the Nautilus FNS filter inherently unsafe when
    used in normal operation. Pentair countered that the explosion in this
    case was caused not by any inherent flaw in the design of the system, but
    rather by an explosive dead-head created by Michaels himself through
    improper and unforeseeable misuse of the FNS canister. Specifically,
    Pentair averred that Michaels improperly installed the FNS filter canister
    onto an obsolete 27-year-old pool filter system that was never designed for
    the FNS canister and contained a device known as a positive shut-off valve
    that could be misused in a way that increased the risk of dead-heads and
    explosions.
    In support of his theory, Michaels presented the testimony of
    Dr. John Manning, an expert in mechanical engineering, as well as Dr.
    Alison Osinski, an aquatics expert. Both generally testified that the
    phenomenon of pool filters exploding under pressure was known in the
    industry, that the design of the FNS filter was unsafe, and that safer
    alternatives existed, including models sold by Pentair that possessed
    automatic external pressure-relief valves and redundant restraints.
    Osinski testified that six different companies offered split-shell filter
    canisters for sale that had redundant restraints and automatic external
    pressure relief valves, and that explosions of split-shell filters having such
    safety features were virtually unknown. In contrast, Osinski noted that
    more than 50 such explosions were known to have occurred with split-
    shell filters sold without such features, many of which had caused serious
    trauma and even death to homeowners. The experts noted that Pentair
    sold a Sta-Rite System 3 split-shell filter with secondary restraints that
    Pentair advertised as "the world's safest and easiest to operate filter." The
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    jury saw internal correspondence written by Pentair employees dated May
    16, 1993, which recognized the danger of filter separation under pressure
    and noted that consumers could be expected to misuse split-shell pool
    filters in a way that could increase the risk of explosion.
    Testimony from several of Pentair's employees confirmed key
    portions of Michaels' allegations. For example, Pentair's chief engineer,
    Ron Robol, testified that he believed the design of the FNS filter was safe.
    However, he agreed that the phenomenon of explosive dead-heads was
    known within the industry, and admitted that at various times Pentair
    had sold split-shell filter canisters equipped with automatic external
    pressure-relief valves designed to reduce the risk of explosion. He
    conceded that when Pentair sold split-shell canisters with automatic
    external air relief valves in the past, those valves worked fine. He also
    agreed that, between 1998 and 2008, Pentair received no claims of filter
    explosions relating to split-shell canisters sold with such automatic valves,
    but had received more than 50 reports of explosions in split-shell models
    sold without those valves. 4 Robol also admitted that filter canisters were
    designed to be cleaned by consumers, and the accidental creation of dead-
    heads, either through improper consumer cleaning, or simply because the
    system was turned on and off repeatedly, was "foreseeable" to
    manufacturers such as Pentair.
    4 The parties vigorously dispute the number of prior explosions in
    their appellate briefing. Michaels contends that 50 explosions were known
    to have occurred in filter canisters of split-shell design similar to the FNS
    canister. On the other hand, Pentair argues that only 4 prior explosions
    were known to have occurred with the FNS canister itself.
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    Similarly, Pentair's product manager of filtration, Robert
    Swindell, agreed through his deposition testimony that a consumer's
    failure to install the canister properly, to clamp it shut, and to release air
    pressure before or during cleaning were all "foreseeable" events. He
    acknowledged that Pentair's Sta-Rite 3 filtration system was safer than
    the FNS because it was held shut by eight individual clamps rather than a
    single clamp. Additionally, Pentair's Vice-President of Engineering,
    Garrett Barkitt, conceded at his deposition that Pentair was aware of
    claims of pool filter separations with its FNS canister, while Pentair
    employee Robert Wilkes admitted that safer alternatives to steel clamps
    existed, including a threaded screw-type ring lock system for which no
    known instances of explosive filter separation had ever been reported. 5
    Pentair's defense focused upon the contention that the FNS
    filter canister was safe, partly because the explosion in this case was
    caused not by any inherent defect in the design of the FNS filter canister,
    but rather by Michaels' own unforeseeable, negligent, and dishonest
    actions. Specifically, Pentair contended that Michaels caused the
    explosion by dead-heading the system while improperly backwashing it,
    and then lied about how the explosion occurred. Pentair suggested that
    Michaels improperly grafted the FNS filter canister onto an older filter
    system that contained a positive shut-off valve that, when incorrectly
    used, would seal the canister and trap air within it, thereby artificially
    5 Pentair also proffered lay witness testimony from Russell Cannon,
    a plumber who knew of no explosion incidents with the FNS canister filter
    during his many years servicing those filters, and from Darren Gagnon, a
    pool filter installer, who testified that he had installed the FNS filter for
    decades, knew of no explosions, and considered it a safe product.
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    creating a dead-head when one otherwise would not have naturally
    occurred.
    During trial, no witness called by either party affirmatively
    testified that Michaels had improperly used the positive shut-off valve to
    create an artificial dead-head within the system. Michaels explicitly
    denied doing so, and no witness identified any evidence suggesting such
    misuse. Instead, Pentair's implication that such misuse may have
    occurred rested upon two prongs. First, after the explosion but before
    trial, Michaels negligently disposed of parts of his pool filtration system,
    including the separation tank, the selector valve attached to the filter, the
    shut-off valves, and various pipes and plumbing. During the trial, Pentair
    requested, and the district court gave, an instruction that permitted the
    jury to make an inference adverse to Michaels based upon the failure to
    preserve the filter system for discovery and tria1. 6 Pentair thus argued to
    the jury that, had the entire filter system been made available for
    inspection, evidence might have been uncovered that indicated Michaels
    seriously misused the system while backwashing it.
    Second, Pentair made Michaels' credibility a major subject of
    the trial. Michaels testified that the canister exploded spontaneously
    when he merely turned the pool filter system on while standing a few feet
    6 The   instruction given by the district court was as follows:
    Twelve: Where relevant evidence which would
    properly be part of this litigation is within the
    control of the plaintiffs whose interest it would be
    to produce it, and they failed to do so without a
    satisfactory explanation, the jury may draw an
    inference that such evidence would have been
    unfavorable to the plaintiffs.
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    away from the system. However, Pentair introduced photos of objects
    lying on the grass near the canister which, Pentair argued, suggested
    Michaels was conducting some kind of maintenance on the filter when it
    exploded. While this contention was disputed by Michaels, medical
    records indicated that Michaels admitted to his physician that he had
    been servicing the filter when it exploded. Michaels also testified during
    trial that he never cleaned the filter himself during the two years he
    owned it, and that he thought the filter was being cleaned by his
    maintenance company, Pool Chlor. However, the owner of Pool Chlor
    testified that the company only managed the chemical levels in the pool
    and never cleaned Michaels' pool filter.
    On cross-examination by Pentair, Michaels' experts agreed
    that their conclusion that Michaels' injury was caused by the defective
    design of the FNS filter was predicated upon Michaels' own description of
    how the explosion occurred, and if Michaels was proven to have lied, then
    their conclusions may no longer be valid. Pentair also argued that certain
    facts proven by Michaels' experts, while true, could be interpreted in
    different ways. For example, Pentair's statistical expert, Dr. Laurentius
    Marais, testified that while Pentair had received 50 reports of explosions
    in filter canisters lacking redundant safety features, those 50 claims must
    be considered in the context of the thousands of canisters sold nationally.
    Thus, in lieu of evidence affirmatively demonstrating that
    Michaels had modified or misused the FNS filter canister in an
    unforeseeable way to cause the explosion, Pentair argued that
    inconsistencies in Michaels' evidence, coupled with the negligent disposal
    of parts of the filter system prior to trial, permitted the jury to infer that
    such a modification or misuse had occurred. Consequently, Pentair
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    argued to the jury that Michaels failed to meet his burden of
    demonstrating by a preponderance of the evidence either that the design
    of the FNS filter was unsafe or that any design defect was the proximate
    cause of his injury.
    ANALYSIS
    On appeal, Michaels asserts various errors. However, because
    the trial court failed to properly analyze the claims of attorney misconduct
    made by Michaels in his post-trial motions under the standard set forth in
    Lioce v. Cohen, 
    124 Nev. 1
    , 
    174 P.3d 970
     (2008), we need only address that
    contention.
    When the losing party in a civil trial alleges in a post-trial
    motion that it is entitled to a new trial because the prevailing party
    committed attorney misconduct during the trial, the Nevada Supreme
    Court has held that the district court must make detailed findings
    regarding the role that the alleged misconduct played at trial and the
    effect it likely had on the jury's verdict.   Id. at 20, 
    174 P.3d at 982
    . See
    BMW v. Roth,      
    127 Nev. 122
    , 141 n.9, 
    252 P.3d 649
    , 661 n.9 (2011)
    (appellate consideration of alleged attorney misconduct that was not the
    subject of specific district court findings "would be contrary to Lioce's
    requirement of specific oral and written findings of misconduct to facilitate
    appellate review of orders granting or denying new trials based on
    attorney misconduct"). In this case, the district court did not make those
    findings. The portion of the district court's written order denying
    Michaels' request for relief due to attorney misconduct simply states that
    "[fin considering plaintiffs allegations under Lioce v. Cohen. . . this Court
    does not find grounds warranting a new trial." The district court's written
    order contains no other findings relating to Michaels' claims of attorney
    misconduct.
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    Ordinarily, we could simply order a limited remand of this
    matter so that the district court can make the required findings.
    However, in reviewing the precedent of the Nevada Supreme Court, some
    of which is quite recent, we take this opportunity to provide guidance to
    the district court on the kinds of findings that must be made. Because the
    district court did not apply the reasoning of these more recent cases, and
    because Lioce itself does not set forth a specific list of what the district
    court's findings must include, we remand this matter to the district court
    to reconsider its conclusions in view of recent precedent and to make the
    findings necessary to support its ultimate decision.
    Standard of review
    A district court's decision to grant or deny a motion for a new
    trial is reviewed for an abuse of discretion.'   Lioce, 124 Nev. at 20, 
    174 P.3d at 982
    . In determining whether such an abuse of discretion occurred,
    'Michaels' district court motion also requested, in the alternative,
    judgment as a matter of law on various grounds. While the denial of a
    post-judgment motion for judgment as a matter of law is not
    independently appealable, see Skender v. Brunsonbuilt Constr. & Dev. Co.,
    
    122 Nev. 1430
    , 1434 n.4, 
    148 P.3d 710
    , 713 n.4 (2006), in this case the
    order denying that motion and Michaels' motion for a new trial were
    entered prior to the final judgment in the underlying case. As a result, the
    order denying Michaels' motion for judgment as a matter of law is an
    interlocutory order, which we can review in the context of Michaels' appeal
    from the final judgment. See Consol. Generator-Nev., Inc. v. Cummins
    Engine Co., 
    114 Nev. 1304
    , 1312, 
    971 P.2d 1251
    , 1256 (1998) (recognizing
    that interlocutory orders entered before final judgment can be reviewed in
    an appeal from the final judgment). However, for reasons discussed
    herein, we limit the scope of this opinion only to the question of attorney
    misconduct. Because attorney misconduct cannot be the basis for entry of
    judgment as a matter of law, in this opinion we address only Michaels'
    request for a new trial.
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    this court must view the evidence and all inferences most favorably to the
    party against whom the motion is made. Grosjean v. Imperial Palace, Inc.,
    
    125 Nev. 349
    , 366, 
    212 P.3d 1068
    , 1080 (2009).
    An attorney may not "encourage [ the jurors to look beyond
    the law and the relevant facts in deciding the case before them."        Lioce,
    124 Nev. at 6, 
    174 P.3d at 973
    . "Under NRCP 59(a)(2), the district court
    may grant a new trial if the prevailing party committed misconduct that
    affected the aggrieved party's substantial rights."      Gunderson v. D.R.
    Horton, Inc., 130 Nev. „ 
    319 P.3d 606
    , 611 (2014).
    In Lioce, the Nevada Supreme Court articulated the applicable
    legal standards governing appellate review of a district court's denial of a
    motion for a new trial based on alleged attorney misconduct.         See Lioce,
    124 Nev. at 14-26, 
    174 P.3d at 978-86
    . Lioce required the district court to
    make post-trial findings on the effect of the misconduct upon the trial, but
    did not delineate the kinds of findings that are required. 
    Id.
     In two recent
    cases, Gunderson v. D.R. Horton, Inc., 130 Nev. , 
    319 P.3d 606
     (2014),
    and BMW v. Roth,       
    127 Nev. 122
    , 
    252 P.3d 649
     (2011), the Nevada
    Supreme Court expanded upon its Lioce analysis and further explained
    how the district court, and appellate courts, should evaluate claims of
    misconduct. The district court in this case did not apply these new cases
    when it decided Michaels' motion, and so we take this opportunity to
    clarify the standard that must be followed in view of those cases.
    Determining whether a new trial is warranted involves the
    application of a three-step analysis. First, we must determine whether
    misconduct occurred.     Gunderson, 130 Nev. at , 319 P.3d at 611.
    Whether an attorney's comments constitute misconduct is a question of
    law reviewed on appeal de novo. BMW, 127 Nev. at 132, 
    252 P.3d at 656
    .
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    If such misconduct has occurred, the next step is to determine the proper
    legal standard to apply in assessing whether the misconduct warrants a
    new trial. Gunderson, 130 Nev. at , 319 P.3d at 611. Finally, we must
    determine whether the district court abused its discretion in applying that
    standard. Id.
    When a party claims misconduct by opposing counsel, the
    legal standard under which that misconduct is reviewed depends on
    whether a timely trial objection was made. See Lioce, 124 Nev. at 17-19,
    
    174 P.3d at 980-82
    . When a timely objection was not made at trial, any
    review of that misconduct, either post-trial by the trial court or on appeal,
    is considerably more circumscribed than if an objection was made. When
    resolving a motion for a new trial based on unobjected-to attorney
    misconduct, "the district court shall first conclude that the failure to object
    is critical and the district court must treat the attorney misconduct issue
    as having been waived, unless plain error exists." Id. at 19, 
    174 P.3d at 982
    . To decide whether there is plain error, the district court must then
    determine "whether the complaining party met its burden of
    demonstrating that its case is a rare circumstance in which the attorney
    misconduct amounted to irreparable and fundamental error."            
    Id.
     And
    "[lin the context of unobjected-to attorney misconduct, irreparable and
    fundamental error is error that results in a substantial impairment of
    justice or denial of fundamental rights such that, but for the misconduct,
    the verdict would have been different." 
    Id.
     Thus, in this case, because no
    objection was lodged at trial, a new trial would only be warranted if
    Pentair committed misconduct and the misconduct amounted to "plain
    error."
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    Plain error requires a party to show 'that no other reasonable
    explanation for the verdict exists." 
    Id.
     (quoting Ringle v. Bruton, 
    120 Nev. 82
    , 96, 
    86 P.3d 1032
    , 1041 (2004)) Analyzing whether such plain error
    has occurred involves weighing the misconduct against the reasonableness
    of the jury's verdict in light of the evidence in the record.   Gunderson, 130
    Nev. at ,319 P.3d at 614 ("In evaluating [the effect of misconduct on a
    verdict], we 'look at the scope, nature, and quantity of misconduct as
    indicators of the verdict's reliability" (quoting Grosjean, 125 Nev. at 365,
    212 P.3d at 1079)). Moreover, the court must consider the "context" in
    which the misconduct occurred. Id.
    Necessarily, then, a determination of whether unobjected-to
    misconduct has created plain error requires balancing the severity of the
    misconduct against the weight of the evidence supporting the jury's
    verdict. In doing so, however, we must bear in mind that "credibility
    determinations and the weighing of evidence are left to the trier of fact."
    See Grosjean, 125 Nev. at 366, 212 P.3d at 1080. Where the record
    demonstrates that the jury's verdict is strongly supported by
    overwhelming evidence, the verdict can generally be explained by the
    evidence itself and even serious misconduct may not warrant a new trial.
    On the other hand, where the evidence in the record is insufficient to
    reasonably explain the jury's verdict even when viewed in the light most
    favorable to the prevailing party, or if it does so only very weakly or
    implausibly, then trial misconduct is likely to have resulted in
    fundamental error, because in those circumstances the jury's verdict was
    more likely to have been a product of the misconduct rather than of a fair
    consideration of the evidence presented.      Id. at 364, 212 P.3d at 1079
    (attorney misconduct warrants new trial in "the rare occasion when the
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    attorney misconduct 'offsets the evidence adduced at trial in support of the
    verdict" (quoting Lioce, 124 Nev. at 19, 
    174 P.3d at 982
    )).
    Furthermore, the court must consider the "context" of the
    misconduct.     Gunderson, 130 Nev. at , 319 P.3d at 614. Misconduct
    that was largely collateral to the principal issues in dispute is less likely to
    have resulted in plain error than misconduct that touched directly upon
    the central questions the jury was asked to resolve. By way of
    hypothetical example, Nevada Rule of Professional Conduct (RPC) 3.4(e)
    prohibits an attorney from stating "a personal opinion as to. . . the
    credibility of a witness." See Lioce, 124 Nev. at 21-22, 
    174 P.3d at 983
    ("[A]n attorney's statements of personal opinion as to the justness of a
    cause, the credibility of a witness, or the culpability of a litigant
    is. . . improper in civil cases and may amount to prejudicial misconduct
    necessitating a new trial."). When an attorney improperly vouches for the
    credibility of an inconsequential witness whose testimony related to a
    collateral issue and whose credibility was never attacked by the opposing
    party, such misconduct likely played a lesser role in the jury's verdict than
    if the attorney vouched for a witness whose credibility was directly
    challenged and whose truthfulness regarding a key issue was the principal
    or sole question for the jury's consideration. Similarly, vouching for the
    credibility of a witness whose testimony was largely cumulative to other
    evidence or irrelevant to the main issues in genuine dispute is less likely,
    in context, to warrant a new trial than if the witness' testimony were the
    only evidence supporting a key contention.
    Finally, the frequency of the misconduct must be considered.
    A single, isolated instance of misconduct is likely to have had a lesser
    impact on the trial than repeated or persistent instances of misconduct.
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    See Gunderson, 130 Nev. at      , 319 P.3d at 612 ("[T]he district court must
    take into account that, by engaging in continued misconduct, the offending
    attorney has accepted the risk that the jury will be influenced by his
    misconduct. . .. although specific instances of misconduct alone might
    have been curable by objection and admonishment, the effect of persistent
    or repeated misconduct might be incurable." (internal quotation omitted)).
    Thus, determining whether "plain error" has occurred as a
    result of unobjected-to misconduct requires the court to closely examine
    the record, weigh the severity and persistence of the misconduct against
    the evidence presented, and assess what role, if any, the misconduct likely
    played in the jury's verdict. See BMW, 127 Nev. at 133, 
    252 P.3d at
    656-
    57.
    Overview of products liability law
    Because alleged attorney misconduct must be evaluated in
    "context," a brief examination of the substantive law that governed the
    trial is necessary. On appeal, the only claim remaining before us is the
    products liability claim, which is a strict liability claim. In Nevada, a
    manufacturer or distributor of a product is strictly liable for injuries
    resulting from a defect in the product that was present when the product
    left its hands. Allison v. Merck Sr Co., Inc., 
    110 Nev. 762
    , 767, 
    878 P.2d 948
    , 952 (1994). "[P]roducts are defective which are dangerous because
    they fail to perform in the manner reasonably to be expected in light of
    their nature and intended function." Ginnis v. Mapes Hotel Corp., 
    86 Nev. 408
    , 413, 
    470 P.2d 135
    , 138 (1970) (internal quotations omitted).
    "Reasonableness" may be determined with reference to such things as
    whether a safer design was possible or feasible, whether safer alternatives
    are commercially available, and other factors. See McCourt v. J.C. Penney
    Co., Inc., 
    103 Nev. 101
    , 104, 
    734 P.2d 696
    , 698 (1987) (stating that
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    "[allternative design is one factor for the jury to consider when evaluating
    whether a product is unreasonably dangerous").
    Furthermore, manufacturers are not necessarily liable for
    injuries caused by a product that was substantially modified or misused by
    the consumer or by an intermediary. "Generally, a substantial alteration
    will shield a manufacturer from liability for injury that results from that
    alteration," but a product manufacturer remains liable if the alteration
    was insubstantial, foreseeable, or did not actually cause the injury. 8
    Robinson v. G.G.C., Inc., 
    107 Nev. 135
    , 140, 
    808 P.2d 522
    ,525 (1991).
    When the risk of danger associated with a product is such that
    it cannot be corrected or mitigated by a commercially feasible change in
    the product's design available at the time the product was placed in the
    stream of commerce, the manufacturer must give adequate warningS to
    consumers of the potential danger. See id. at 138, 
    808 P.2d at 524
    . Where
    a plaintiff alleges that such warnings were not adequately given, the
    "plaintiff carries the burden of proving, in part, that the inadequate
    warning caused his injuries." Rivera v. Phillip Morris, Inc., 
    125 Nev. 185
    ,
    190, 
    209 P.3d 271
    , 274 (2009).
    8 Because  products liability claims allege strict liability, comparative
    negligence is not a defense to a prima facie case of such liability. Maduike
    v. Agency Rent-a-Car, 
    114 Nev. 1
    , 7, 
    953 P.2d 24
    , 27 (1998)
    ("[Clomparative negligence reductions do not apply when the claim is
    based on strict liability."). Comparative fault is, however, a defense to a
    negligence claim. Thus, even though the only claim on appeal before us is
    the strict liability cause of action, evidence of comparative fault was
    admitted and argued at trial in connection with Michaels' negligence
    claim.
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    Michaels' assertions of attorney misconduct
    Michaels argues that, during closing argument, Pentair's
    counsel made various impermissible statements that were not based in
    evidence or that reflected the personal opinion of counsel. Michaels'
    counsel did not timely object to any of the statements now cited as error on
    appeal.
    In Lioce, the Nevada Supreme Court directed district courts
    confronted with post-trial motions alleging attorney misconduct as follows:
    [We now require that, when deciding a motion for
    a new trial, the district court must make specific
    findings, both on the record during oral
    proceedings and in its order, with regard to its
    application of the standards described above to the
    facts of the cases before it. In doing so, the court
    enables our review of its exercise of discretion in
    denying or granting a motion for a new trial.
    124 Nev. at 19-20, 
    174 P.3d at 982
    . See also BMW, 127 Nev. at 141 n.9,
    
    252 P.3d at
    661 n.9.
    Conceivably, in some cases in which a district court fails to
    make requisite findings in support of a decision, that decision may
    nonetheless be affirmed on appeal if the record as a whole demonstrates
    that the ultimate conclusion was correct even if the reasons for it are not
    clearly articulated. For example, if the most cursory review of the briefs
    or the record clearly demonstrates that no misconduct occurred as a
    matter of law, then a remand for the district court to simply state the
    obvious would seem wasteful and unnecessary. During oral argument,
    Pentair's counsel suggested that a remand in this case was unnecessary
    for precisely this reason. Had our review of the record in this case clearly
    indicated either that no misconduct occurred, or that any attorney
    misconduct that occurred could not possibly have affected the jury's
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    verdict, then we could perhaps resolve this appeal based upon the record
    alone without the need for additional findings by the district court.
    In this case, however, the record reveals that Pentair's
    attorney made a variety of statements during closing argument that could
    plausibly constitute the kind of attorney misconduct that concerned the
    Nevada Supreme Court in Lioce. 9 For example, Pentair's counsel
    appeared to vouch for a witness, Dr. Casey (Michaels' treating physician
    who contradicted Michaels' version of events), by stating that "I think he
    is a credible and honest witness." Counsel also appeared to offer opinions
    about other witnesses, including witnesses from Pool Chlor, stating "I
    don't know about you, but I know what I thought about those people's
    testimony.'qo By offering personal opinions about the credibility of
    °In Lioce, the Nevada Supreme Court conducted a detailed analysis
    of the scope and severity of the alleged misconduct before concluding that
    a remand for additional findings was necessary; indeed, the supreme court
    went so far as to conclude that misconduct occurred as a matter of law
    before remanding. 124 Nev. at 20-25, 
    174 P.3d at 982-85
    . In this opinion,
    we are not required to go that far.
    ImCounsel's closing argument contains other injections of personal
    opinion, such as: "Why is Mr. Michaels ... saying that he is looking away
    from the plate? Why is he saying that?. . . I'll give you what I think the
    answer is."; "I don't think that is the physical evidence. I don't think the
    physical evidence supports that"; "I have an explanation for you—for your
    consideration as to what I think is consistent with the physical evidence in
    this case. I think the lid did separate up. . . . I think what was happening
    was Mr. Michaels just cleaned and back washed and cleaned the filter that
    day.. . . So I think that what happened is he cleaned it"; "I don't think
    Sunrise Hospital Medical Center is going to do that"; "I really think we all
    know what really happened." Counsel even proffered his own personal
    medical diagnosis of the severity of Michaels' injuries and how they were
    incurred, arguing that "if he fell straight down on concrete, you think his
    head would be swollen. I do."
    COURT OF APPEALS
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    witnesses, Pentair's counsel may have violated RPC 3.4(e), which states
    that, during the course of a trial, an attorney shall not state "a personal
    opinion as to. . . the credibility of a witness." See Lioce, 124 Nev. at 21-22,
    
    174 P.3d at 983
     ("[A]n attorney's statements of personal opinion as to the
    justness of a cause, the credibility of a witness, or the culpability of a
    litigant is .. . improper in civil cases and may amount to prejudicial
    misconduct necessitating a new trial."). The district court's written order
    fails to indicate whether the court fully considered these arguments,
    whether it concluded that they did not constitute misconduct, or whether
    it instead concluded that they represented misconduct but that no
    fundamental error occurred."
    Another instance of potential misconduct appeared to occur in
    relation to the adverse inference jury instruction given by the trial court.
    An adverse inference instruction may be given when a district court
    concludes that particular evidence was negligently destroyed.         Franchise
    Tax Bd. of Cal. v. Hyatt, 130 Nev. ,           
    335 P.3d 125
    , 152 (2014), cert.
    "We note that this was a two-week jury trial and the trial transcript
    appears not to have been available to the district court when it considered
    Michaels' motion, and therefore we acknowledge that it may well be easier
    for us to scour the record and locate these statements now than it was for
    the district court when the motion was first presented. We also note that
    official transcripts of the trial may not be available when a district court is
    confronted with post-trial motions alleging attorney misconduct, because
    the deadline for filing a motion for new trial expires ten days after entry of
    judgment, NRCP 59, and in longer trials the full transcript may not be
    available until well after that time period has elapsed. Thus, in many
    cases it may be difficult for the parties to fully cite to specific instances of
    misconduct in their post-trial briefing and for the district court to make
    precise findings, especially when the precise wording of an attorney's
    argument is disputed.
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    granted in part, 576 U.S.       , 
    135 S. Ct. 2940
     (2015). The adverse
    inference instruction "merely allows the fact-finder to determine, based on
    other evidence, that a fact exists." 
    Id.
     The adverse inference instruction
    in this case (jury instruction number 12) was given by the court as a
    sanction for very specific conduct, namely, Michaels' negligent disposal of
    pieces of the filter system before trial. But during closing argument,
    Pentair's counsel appeared to invite the jury to apply this instruction to
    other evidence that had no relation either to the discovery violation, the
    district court's sanction, or the purpose of the instruction given by the
    court. Specifically, Pentair's counsel argued that the adverse inference
    instruction applied to a plumbing expert that Michaels purportedly
    retained. Counsel argued:
    There is another expert they didn't bring in, where
    you could think that maybe that expert wasn't
    going to say good things. Who did the plaintiffs
    call, the plaintiffs lawyer, right after the accident
    to come and take [pictures]. I don't remember the
    gentleman's name, but he was a plumbing expert.
    That much I remember. Remember Mr. Kesky. I
    played his deposition. . . . He said [that he]
    discussed the plumbing issues with the expert.
    But did the plaintiffs bring him in here. . . . Is
    there a reason for that. I remind you of the
    instruction, where the plaintiffs have the evidence,
    because they are the only ones in control of that
    expert, he was the one that has his investigator
    there, not us, Pentair had no chance at any of this,
    you take it against [Michaels].
    However, the record does not appear to indicate that any such plumbing
    expert was ever retained by Michaels; the district court did not make any
    findings on this question. Furthermore, even if a plumbing expert had
    been retained, counsel's invitation for the jury to apply the adverse
    inference instruction to Michaels' failure to call that witness is
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    problematic because the adverse inference instruction was not given as a
    sanction for that conduct. 12
    Consequently, we cannot conclude from the record that
    attorney misconduct was so clearly absent from the trial that additional
    findings by the district court would be superfluous and unnecessary.' 3 We
    also cannot conclude that the instances of potential misconduct that
    appear in the record were necessarily so minor or irrelevant that they
    must be found by the district court to have played no role whatsoever in
    the jury's verdict. In this case, the jury found in favor of Pentair, but the
    evidence supporting that verdict was far from overwhelming or clear.
    Several of Pentair's witnesses conceded the essential points that Pentair
    knew of prior explosions occurring in split-shell filters and that safer
    alternatives to such filter designs were commercially feasible. Similarly,
    12According    to the deposition testimony of Terry Keskey, a plumbing
    company visited Michaels' home shortly after the explosion. But under
    Nevada law, merely consulting a plumber in the wake of a pool explosion
    does not equate to retaining an expert who must, or is even qualified to,
    testify at trial. See Higgs v. State, 
    126 Nev. 1
    , 16, 
    222 P.3d 648
    , 658 (2010)
    ("NRS 50.275 is the blueprint for the admissibility of expert witness
    testimony" and a witness is not permitted to be qualified as an expert
    unless certain specific legal requirements have been satisfied).
    '3 We emphasize that, by including these observations, we do not
    conclude that the arguments cited here necessarily represented reversible
    misconduct; the district court must make the necessary findings on
    remand before they can be considered by us on appeal. Conversely, we
    also do not intend to suggest that any instances of alleged misconduct
    cited by Michaels but omitted from our discussion could not have
    constituted misconduct. Rather, we include these particular instances
    merely as illustrations in response to Pentair's contention that a remand
    is unnecessary because the district court could not possibly have concluded
    that reversible misconduct occurred at any point in the trial.
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    Pentair did not present any substantive evidence that Michaels
    unforeseeably misused or modified the FNS filter in any way. 14 Rather, in
    the absence of substantive evidence, Pentair invited the jury to infer that
    such unforeseeable modifications might have happened because some
    pieces of thefl filter system were missing and because the testimony of
    Michaels' witnesses was supposedly not credible. Thus, at least some of
    the apparent misconduct in this case related to the heart of Pentair's
    defense strategy and to the most important questions the jury was asked
    to answer. Under these circumstances, we cannot conclude that the
    alleged misconduct related only to matters of no consequence and could
    not possibly have resulted in fundamental injustice. Thus, in this case,
    the record indicates that misconduct could be deemed to have occurred,
    and that the evidence supporting the products liability verdict was weak.
    However, in the absence of detailed findings, we cannot determine
    whether no other reasonable explanation exists for the verdict but the
    alleged misconduct.
    In this case, had the district court engaged in a comprehensive
    analysis, it could have concluded that misconduct occurred and that the
    misconduct was both severe and repeated.      See Gunderson, 130 Nev. at
    NA number of Pentair's employees and engineers conceded that
    accidental dead-heads during cleaning were foreseeable. Thus, even if it
    were true that Michaels had caused such a dead-head to occur while
    cleaning the filter canister, as Pentair's counsel suggested during his
    closing argument, such a conclusion may have been legally irrelevant to
    the question of whether the FNS filter was improperly designed.
    Comparative negligence is not a defense to strict liability, and therefore
    even if Michaels had improperly dead-headed the system while cleaning it,
    Pentair may still be liable for manufacturing a dangerous product so long
    as dead-heading was a foreseeable event.
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    (0) 1947B    oflapp
    , 319 P.3d at 612. Furthermore, when viewed in context, the district
    court could have concluded that the misconduct played a critical role in
    the case. See id. at , 319 P.3d at 614 (instances of misconduct must be
    evaluated "as determined by their context"); see also Grosjean v. Imperial
    Palace, Inc., 
    125 Nev. 349
    , 364, 
    212 P.3d 1068
    , 1079 (2009).
    Accordingly, the record in this case is not so clear that detailed
    findings by the district court are clearly unnecessary. Furthermore, the
    district court's failure to engage in the exercise of making specific and
    detailed findings particularly matters when the district court acted
    without considering the Nevada Supreme Court's reasoning in BMW and
    without the benefit of Gunclerson.1-5 Had such detailed findings been
    made, we could more easily determine •whether those new cases would
    have affected the district court's analysis. Therefore, we must remand
    this matter to the district court for additional findings and further direct
    the district court to reconsider its conclusion in view of these cases and the
    standard set forth in this opinion. 16
    On remand, the district court must clarify, at a minimum,
    whether it found that no misconduct occurred or rather whether it
    concluded that misconduct did occur but was harmless under the
    16 The district court also did not have the benefit of the Nevada
    Supreme Court's recent decision in Franchise Tax Board of California v.
    Hyatt, 130 Nev. at , 335 P.3d at 152, cert. granted in part, 576 U.S. ,
    
    135 S. Ct. 2940
     (2015), which clarified the law relating to adverse
    inference instructions resulting from lost evidence.
    16 The  only issue presented to us in this appeal concerned the
    products liability claim, and therefore this remand is limited only to that
    claim. Because Michaels did not present argument on the other claims for
    relief adjudicated below, we do not disturb those portions of the verdict,
    and the district court need not address those claims on remand.
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    (0) 19478 •24S0
    standards of Lioce in view of: (1) the nature of the claims and defenses
    asserted by the parties; (2) the relative strength of the evidence presented
    by the parties; (3) the facts and evidence that were either disputed or not
    substantively disputed during the trial; (4) the type, severity, and scope of
    any attorney misconduct; (5) whether any misconduct was isolated and
    incidental on the one hand or repeated and persistent on the other; (6) the
    context in which any misconduct occurred; (7) the relationship of any
    misconduct to the parties' evidence and arguments; and (8) any other
    relevant considerations.
    In reviewing these factors, the district court's ultimate goal is
    to assess whether any misconduct "offsets the evidence adduced at trial"
    such that "no other reasonable explanation for the verdict" exists but that
    it was the product of the misconduct. See Grosjean, 125 Nev. at 363, 212
    P.3d at 1079 (internal quotations omitted). In doing so, the district court
    must "assume that the jury believed all of the evidence favorable to" the
    party against whom the motion is made.       Id. at 366, 212 P.3d at 1080.
    Nevertheless, when serious and repeated attorney misconduct has
    demonstrably occurred, the district court's deference to the jury is more
    limited than if such misconduct had not occurred, and the trial court must
    carefully consider whether the misconduct led the jury astray and caused
    it to base its verdict upon something other than the evidence and the
    applicable law.
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    CONCLUSION
    For the foregoing reasons, we vacate the district court's denial
    of Michaels' motion for new trial and remand this matter to the district
    court for further proceedings consistent with this opinion.
    J.
    Tao
    I concur:
    , C.J.
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    (0) 1947F1
    SILVER, J., concurring:
    I concur in the result only. In my view, the majority decision
    prematurely highlights portions of the alleged misconduct during closing
    argument and unnecessarily comments on the strength of the evidence
    presented at trial. Yet, the majority also acknowledges that the district
    court seemingly did not have the benefit of transcripts when it considered
    the new trial motion due to the timing involved in such post-trial motions,
    and that it did not have the benefit of authority and guidance from the
    supreme court's decision in Gunderson v. D.R. Horton, Inc., 130 Nev. ,
    
    319 P.3d 606
     (2014). The majority further notes that, in denying the new
    trial motion, the district court did not consider the supreme court's
    reasoning in BMW v. Roth, 
    127 Nev. 122
    , 
    252 P.3d 649
     (2011). No further
    instruction or analysis is required for this court to resolve this appeal.
    Therefore, a limited remand in this matter directing the district court to
    make detailed findings regarding specific instances of alleged misconduct
    would have sufficed. Respectfully, I concur with only the result reached by
    the majority.
    1/41,:eae.3               , J.
    Silver
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