McCoy v. Whirlpool Corp. , 287 F. App'x 669 ( 2008 )


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  •                                                                            FILED
    United States Court of Appeals
    Tenth Circuit
    July 22, 2008
    Elisabeth A. Shumaker
    UNITED STATES COURT OF APPEALS                   Clerk of Court
    FOR THE TENTH CIRCUIT
    JAMES B. McCOY, on behalf of himself,
    and LORRAY McCOY, Deceased, as
    heirs of Emily M. McCoy, and as
    Administrator of the Estate of Emily M.
    McCoy; AMERICAN NATIONAL
    PROPERTY & CASUALTY                                       No. 05-3337
    COMPANY,                                         (D. C. No. 2:02-CV-2064-KHV)
    (D. Kansas)
    Plaintiffs-Appellants,
    v.
    WHIRLPOOL CORPORATION,
    Defendant-Appellee.
    ORDER
    Before TACHA, Circuit Judge, EBEL, Senior Circuit Judges, and KANE, Senior
    District Judge.*
    On December 5, 2007, we issued an order and judgment in this case reversing the
    district court’s July 29, 2005 Judgment entered in favor of Defendant Whirlpool
    *
    The Honorable John L. Kane, Senior District Judge, United States District Court
    for the District of Colorado, sitting by designation.
    Corporation and remanding for entry of judgment in favor of Plaintiffs based on the
    February 10, 2005 jury verdict. The opinion contained no instructions to the district
    court concerning an award of post-judgment interest. See McCoy v. Whirlpool Corp.,
    258 F. App’x 189 (10th Cir. Dec. 5, 2007) (unpublished).
    This appeal is presently before the court based on Plaintiffs’ motion pursuant to
    Fed. R. App. P. 37(b) to recall the mandate to include instructions for post-judgment
    interest, Defendant’s reply in opposition, Plaintiffs’ reply in support of their motion, and
    Defendant’s response in opposition.
    Upon consideration, the motion to recall is GRANTED. The mandate issued
    January 9, 2008 is RECALLED.
    The December 5, 2007 order and judgment is amended to instruct the district
    court to award post-judgment interest to Plaintiffs from the date of the original judgment
    entered on July 29, 2005 by the district court.
    This order shall act as a supplement to the mandate issued originally by this court
    on January 9, 2008.
    Entered for the Court,
    Elisabeth A. Shumaker, Clerk
    FILED
    United States Court of Appeals
    Tenth Circuit
    December 5, 2007
    UNITED STATES COURT OF APPEALS
    Elisabeth A. Shumaker
    Clerk of Court
    FOR THE TENTH CIRCUIT
    JAMES B. McCOY, on behalf of himself,
    and LORRAY McCOY, Deceased, as heirs
    of Emily M. McCoy, and as Administrator
    of the Estate of Emily M. McCoy;
    AMERICAN NATIONAL PROPERTY &                               No. 05-3337
    CASUALTY COMPANY,                                  (D.C. No. 02-CV-02064-KHV)
    (D. Kansas)
    Plaintiffs-Appellants,
    v.
    WHIRLPOOL CORPORATION,
    Defendant-Appellee.
    ORDER AND JUDGMENT**
    Before TACHA, Chief Circuit Judge, EBEL, Senior Circuit Judge, and KANE, Senior
    District Judge.***
    James B. McCoy and American National Property & Casualty Company brought
    this action against Whirlpool Corporation for wrongful death and property loss resulting
    from a fire at the McCoy home. Following a trial in which the jury returned a verdict for
    **
    This order and judgment is not binding precedent, except under the doctrines of
    law of the case, res judicata, and collateral estoppel. The court generally disfavors the
    citation of orders and judgments; nevertheless, an order and judgment may be cited under
    the terms and conditions of 10th Cir. R. 36.3.
    ***
    The Honorable John L. Kane, Senior District Judge, United States District
    Court for the District of Colorado, sitting by designation.
    the plaintiffs, the district court entered judgment as a matter of law in favor of the
    defendant. Plaintiffs appeal. We exercise jurisdiction pursuant to 
    28 U.S.C. § 1291
     and
    reverse.
    Background
    On the evening of February 16, 2000, Lorray McCoy loaded the dishwasher at her
    family’s home and set its timer to start a wash cycle after a delay of five hours.
    Mrs. McCoy and her daughter, Shelley, went to bed some hours later. Just as
    Mrs. McCoy was falling asleep, she smelled smoke and got out of bed to investigate.
    Mrs. McCoy testified at trial that she discovered flames coming out of the dishwasher and
    igniting the curtains and wall above it. Mrs. McCoy called to her daughter, but Shelley
    was unable to escape and died in the fire. The McCoys’ home was destroyed.
    James B. and Lorray McCoy and their insurer, American National Property and
    Casualty Company, (collectively “Plaintiffs”) filed separate suits against Whirlpool
    Corporation (“Whirlpool”) as the manufacturer of the dishwasher.1 The suits alleged the
    fire was caused by a manufacturing defect in the dishwasher and sought damages for
    wrongful death and property loss based on a strict liability theory. The cases were
    consolidated and tried to a jury in August, 2003. After the jury deadlocked, the case was
    retried in early 2005. On February 10, 2005, the jury in the second trial returned a verdict
    finding for Plaintiffs and awarding them $1,712,914.
    1
    Mrs. McCoy is now deceased.
    2
    During the second trial, the district court had taken under advisement oral motions
    by Whirlpool for directed verdict and judgment as a matter of law. Whirlpool renewed
    these motions following the verdict. On July 29, 2005, the district court granted
    Whirlpool’s motions and directed that judgment be entered in its favor. The district court
    based its decision on two findings: (1) the testimony of James T. Martin, one of
    Plaintiffs’ experts, as to general and specific causation was unreliable and hence
    inadmissible under Rule 702; and (2) with or without Martin’s testimony, Plaintiffs had
    failed to present sufficient evidence to carry their burden of proving that a specific defect
    in Whirlpool’s dishwasher had caused the fire. On appeal, Plaintiffs challenge both
    findings and the district court’s entry of judgment for Whirlpool.
    Discussion
    I.     Martin’s Expert Testimony
    Expert testimony must be both relevant and reliable to be admissible. See Daubert
    v. Merrell Dow Pharm., Inc., 
    509 U.S. 579
    , 589, 594-95 (1993); Fed. R. Evid. 702. The
    district court must act as the “gatekeeper” with respect to proffered expert testimony to
    ensure that it meets both of these requirements. See Daubert, 
    509 U.S. at 589
    ; Bitler v.
    A.O. Smith Corp., 
    400 F.3d 1227
    , 1232 (10th Cir. 2004). This role requires the district
    court “to assess the reasoning and methodology underlying the expert’s opinion, and
    determine whether it is both scientifically valid and applicable to a particular set of facts.”
    Dodge v. Cotter Corp, 
    328 F.3d 1212
    , 1221 (10th Cir. 2003). We review de novo
    whether the district court performed this “gatekeeper” function and applied the proper
    3
    legal standards in doing so. Dodge, 
    328 F.3d at 1223
    ; see Bitler, 400 F.3d at 1232. We
    review for abuse of discretion the procedures utilized by the district court in acting as
    gatekeeper, and its ultimate determination on whether to admit or exclude expert
    testimony under the proper legal standard. Dodge, 
    328 F.3d at 1223
    ; see Bitler, 400 F.3d
    at 1232. We will not find abuse of discretion, however, unless we are convinced that the
    district court’s procedures or ultimate determination were “arbitrary, capricious,
    whimsical, manifestly unreasonable, or clearly erroneous.” Bitler, 400 F.3d at 1232; see
    Dodge, 
    328 F.3d at 1223
    .
    In this case, the district court examined Mr. Martin’s expert testimony after the
    trial and determined that his opinions as to general and specific causation, that is, whether
    the McCoy fire could result from a manufacturing defect and did result from such a
    defect, were not sufficiently reliable to be admitted under Rule 702. See McCoy v.
    Whirlpool Corp., 
    379 F. Supp. 2d 1187
    , 1196-1202 (D. Kan. 2005). Accordingly, our
    task is to determine de novo whether the district court applied the proper legal standard in
    making its reliability determination, and, if so, whether this determination and the
    decision to exclude Martin’s testimony were an abuse of discretion.
    Martin’s expert testimony at trial addressed whether the McCoy fire was caused by
    a manufacturing defect in the Kenmore New Generation dishwasher in the McCoy home.
    The New Generation dishwashers, which are manufactured by Whirlpool, contain a door
    latch switch assembly located at the top center of the dishwasher door. The assembly
    includes two “microswitches” designed to control electrical current to the dishwasher
    4
    based on whether the dishwasher door is open or shut. When the dishwasher door is shut
    and latched, a plunger within each microswitch is mechanically depressed and allows
    electrical contacts inside the microswitch to touch so that electrical current passes to the
    dishwasher. In this position, the microswitch is said to be “closed.” When the
    dishwasher door is open and unlatched, the plunger retracts to separate the electrical
    contacts and automatically turn off the current and hence dishwasher operations. In this
    position, the microswitch is said to be “open.”
    Each microswitch also includes two metal tabs that extend outside the microswitch
    and connect with a flag terminal. Each flag terminal then utilizes a crimp attachment to
    connect the terminal to conductors in the wiring harness of the dishwasher. The total
    current demand for the dishwasher passes through the microswitches and connectors
    when the dishwasher door is closed and the microswitches are in the closed position.
    When Whirlpool first began manufacturing the New Generation dishwashers in
    1990, it used flag terminals manufactured by AMP in the door latch switch assemblies.
    Several years later, after experiencing overheating and fire problems at the AMP flag
    terminals, Whirlpool substituted flag terminals manufactured by ETCO. At
    approximately the same time that it made this change, Whirlpool also stopped using white
    microswitches in some New Generation dishwashers and replaced them with black
    microswitches, which are made of a different material than their white counterparts. This
    change was not related to overheating problems or safety concerns. The door latch switch
    5
    assembly in the McCoy dishwasher, which was manufactured in 1996, had black
    microswitches and ETCO flag terminals.
    Plaintiffs alleged at trial that the McCoy fire resulted from an electrical fire caused
    by a manufacturing defect in the family’s dishwasher, specifically a defect in the
    electrical circuitry of the door latch switch assembly at either the attachment of the flag
    terminals to the microswitches or the flag terminals to the wire conductors. In support of
    these allegations, Plaintiffs presented testimony from four fire origin and causation
    experts, each of whom investigated the McCoy fire and concluded it originated in the
    McCoy’s dishwasher. Three of Plaintiffs’ fire experts further opined that the fire began
    in the area of the dishwasher’s door latch switch assembly and that its cause was
    electrical in nature. Two of these three described the fire more specifically as resulting
    from abnormal electricity or an abnormality in the dishwasher’s electrical system.
    Another expert investigated the potential sources of an electrical fire in the McCoy home
    and testified that the only potential source that he could not eliminate was the dishwasher.
    This testimony was admitted by the court and is not challenged on appeal.
    Plaintiffs also presented the expert opinion testimony of James T. Martin, an
    electrical engineer with experience in investigating fires involving dishwashers.
    Mr. Martin’s testimony was directed at the mechanism by which an electrical fire could
    originate in the door latch switch assembly area of the McCoy dishwasher, and whether
    such a fire would be the result of a manufacturing defect. Mr. Martin testified he formed
    his opinions based on application of electrical engineering principles and standards to
    6
    information he gathered through a review of thousands of pages of Whirlpool documents
    regarding the electrical circuit design of its New Generation dishwashers, the results of
    Whirlpool testing of these dishwashers, deposition testimony of Whirlpool engineers and
    Plaintiffs’ fire origin and cause experts, and his own inspection of the remains of the
    McCoy dishwasher and other Whirlpool dishwashers.
    Based on this methodology, Mr. Martin testified that in his opinion an electrical
    fire in the door latch switch assembly area would result from excessive resistance heating
    occurring at a loose or improper connection in the electrical circuitry of the assembly. He
    explained that resistance heating has a cumulative or cascading effect because each
    incident of resistance heating changes the physical properties of the heating point, so that
    the next incident produces increased heating and higher temperatures. Mr. Martin
    identified three connection points in the door latch switch assembly at which excessive
    resistance heating might occur – the connections between the microswitch and flag
    terminals, between the terminals and conductors, and within the microswitch – but
    focused on the potential for resistance heating at the attachments of the flag terminals to
    the microswitch and particularly to the conductor. He testified that an improperly sized
    or loose crimp in the McCoy dishwasher at these locations was a manufacturing defect
    that could result in excessive resistance heating, that this excessive resistance heating
    could over time reach temperatures that would ignite surrounding combustibles, and that
    he had seen examples of fires caused by this mechanism in dishwashers manufactured by
    Whirlpool. Mr. Martin also testified that if the McCoy fire originated in an electrical fire
    7
    in the dishwasher’s door latch switch assembly, as Plaintiffs’ fire origin and causation
    experts had testified, then it was his opinion that the specific cause of the McCoy fire was
    excessive resistance heating occurring in the current flow path caused by a manufacturing
    defect in the connection between the flag terminal and either the conductor or
    microswitch.
    At trial, Whirlpool argued that Mr. Martin’s expert opinion testimony that the
    McCoy fire could and did result from a manufacturing defect was unreliable and hence
    inadmissible under Rule 702 because he had not adequately addressed a countering expert
    opinion presented by Whirlpool engineer Ernest Grunewald. Mr. Grunewald agreed with
    Mr. Martin that if the McCoy fire originated in the door latch switch assembly area as
    opined by Plaintiffs’ fire science experts, then the cause of the fire was a manufacturing
    defect in the electrical circuitry in this area.2 He testified further, however, that in his
    opinion the McCoy fire could not have originated in this area because the black
    microswitches in the McCoy dishwasher’s door latch switch assembly would have acted
    as thermal fuses to cut off electricity and thus halt excessive resistance heating in this area
    before a fire could ignite.3 Mr. Grunewald based this conclusion on the 160° C
    2
    Mr. Grunewald testified that something other than a manufacturing defect
    in the electrical circuitry of the door latch switch assembly, such as improper servicing of
    this assembly, could cause a fire in this area in some circumstances, but acknowledged
    that there was no evidence of these circumstances with respect to the McCoy dishwasher.
    3
    Both Mr. Grunewald and Mr. Martin testified that a thermal fuse is a device
    designed to halt the flow of electricity through a circuit when the temperature in the
    vicinity of the thermal fuse reaches a specific level.
    8
    temperature at which he reported the plungers in the black microswitches would melt,
    which he testified would cause the electrical contacts in the switches to open and stop
    current flowing through the switches well before resistance heating could produce high
    enough temperatures to ignite surrounding combustibles. Mr. Grunewald also based his
    testimony on his personal experience with black microswitches during his long tenure as
    a Whirlpool engineer.
    Mr. Grunewald acknowledged in his testimony that the black microswitches were
    not designed to serve as thermal fuses and had not been tested or designated as thermal
    safety devices by the manufacturer or others. He also testified that Whirlpool had
    reported in testing their New Generation dishwashers that the black microswitches
    sometimes failed in a closed position (the position that conducts electricity) when the
    plunger melted in the presence of excessive heat resistance, and that there were instances
    in which fires had ignited in door latch switch assemblies containing black
    microswitches. Mr. Grunewald opined, however, that these test and fire reports were
    either erroneous, based on his physical inspection of the switches in question in
    connection with this litigation, or otherwise could be explained in a manner consistent
    with his opinion that a fire could not originate in the door latch switch assembly in the
    presence of the black microswitches.
    In response to Mr. Grunewald’s testimony, Mr. Martin testified it would be a
    totally by-chance event for a microswitch to function as a thermal fuse, that it was not
    good engineering science to suggest that a switch that had not been designed or tested as
    9
    thermal fuse in fact reliably functioned as one, that Whirlpool tests had shown that the
    black microswitches did not always shut off electricity when temperatures reached the
    plungers’ melting point, and that if Plaintiffs’ fire and origin experts were correct that the
    McCoy fire originated as an electrical fire in the door latch switch assembly area of the
    McCoy’s dishwasher, then the black microswitch, by definition, had not functioned as a
    thermal fuse.
    At trial, the district court rejected Whirlpool’s challenge to Mr. Martin’s testimony
    and admitted it upon finding that the scientific methodology Mr. Martin had employed in
    reaching his opinions was customary and generally accepted in the electrical engineering
    field.4 Whirlpool’s arguments concerning the black switch-thermal fuse theory and
    Mr. Martin’s response to it, the district court found, went only to the weight the jury
    might accord Mr. Martin’s testimony. After trial, however, the district court reversed
    itself, holding that Mr. Martin’s testimony was not sufficiently reliable to be admitted
    under Rule 702.5
    The role of the district court in assessing the reliability of an expert’s opinion
    under Rule 702 is simply to determine whether the methodology “employed by the expert
    in reaching the conclusion is scientifically sound and that the opinion is based on facts
    4
    In so holding, the district court accepted Mr. Martin’s testimony that it was not
    standard practice in the field, or even possible in many instances, to do physical testing to
    confirm that a particular defect had caused an electrical fire.
    5
    There is no dispute on appeal that Mr. Martin’s expert opinion testimony met the
    other requirements for admission under Rule 702.
    10
    which sufficiently satisfy Rule 702's reliability requirements.” Bitler, 400 F.3d at 1233.
    Here, there is no question that Mr. Martin, in relying on electrical circuitry information,
    test results and other materials provided by Whirlpool, as well as his inspection of the
    McCoy and other Whirlpool dishwashers, based his conclusions on facts satisfying
    Rule 702's reliability requirements. The district court also found at trial and reiterated in
    its post-trial decision that the method employed by Mr. Martin in reaching his conclusions
    about the potential causes of excessive resistance heating in the door latch switch
    assembly was generally accepted and scientifically reliable. Aplt. App. at 2099; McCoy,
    
    379 F. Supp. 2d at 1201
    . The only basis cited by the district court for nonetheless finding
    Mr. Martin’s methodology insufficiently reliable for admission of his causation opinions
    was that Mr. Martin had not explained how excessive resistance heating could cause a fire
    in a New Generation dishwasher equipped with black microswitches. McCoy,
    
    379 F. Supp. 2d at 1198-99
    .
    Excluding Mr. Martin’s testimony on this basis was an abuse of discretion. The
    linchpin of the district court’s analysis is its acceptance of Mr. Grunewald’s opinion
    testimony that black microswitches always function as thermal fuses. See, e.g., McCoy,
    
    379 F. Supp. 2d at
    1197 n.14 (describing black microswitches as “thermal protective
    devices”), 1199 (criticizing Mr. Martin for ignoring “undisputed and known evidence
    about the thermal properties of black microswitches”), 1201 (holding Mr. Martin’s
    testimony was not sufficiently reliable because it did “not address the thermal protective
    function that black microswitches perform.”). In so doing, the district court necessarily
    11
    assessed Mr. Grunewald’s testimony on this issue and found it credible and persuasive.
    Such determinations, however, are reserved for the finder of fact, and may not be relied
    upon by a district court in deciding whether to admit or exclude an opposing expert’s
    conflicting testimony. See Rink v. Cheminova, Inc., 
    400 F.3d 1286
    , 1293 n.7 (11th Cir.
    2005); Jahn v. Equine Servs., PSC, 
    233 F.3d 382
    , 391 (6th Cir. 2000).
    Whirlpool and the district court assert that our decision in Truck Insurance
    Exchange v. Magnetek, Inc., 
    360 F.3d 1206
     (10th Cir. 2004), is factually on “all fours”
    with this case and requires exclusion of Mr. Martin’s testimony. We disagree. In
    Magnetek, the plaintiff alleged that defective ballast in a fluorescent light fixture had
    ignited a fire that destroyed the plaintiff’s building. It was undisputed that the ballast
    contained a thermal protective device specifically designed to shut off power to the
    fixture if the temperature exceeded 232° Fahrenheit, well below the approximately 400° F
    temperature generally believed necessary to ignite the wood in the fixture’s vicinity. 
    Id. at 1208
    . The parties in Magnetek further stipulated that the thermal protective device in
    the ballast functioned properly throughout the fire, meaning that it cut off current to the
    fixture before the generally accepted ignition temperatures were reached. 
    Id.
     In order to
    prove causation, therefore, the plaintiff was required to present evidence that ignition
    could have occurred in the lower temperature range allowed by the thermal protective
    device. See 
    id. at 1209, 1211
    . The plaintiff produced expert evidence that the ballast
    could have ignited the fire even at these lower temperatures, but the district court
    excluded the expert’s testimony after determining, based on review of relevant scientific
    12
    literature, that the scientific theory underlying this low-temperature ignition hypothesis,
    the theory of pyrolysis, was insufficiently reliable to form the basis of expert testimony.
    
    Id. at 1211
    . See 
    id.
     We affirmed on appeal.
    In this case, there is no stipulation that the door latch switch assembly contained a
    thermal protective device of any kind. Nor can it be said that Whirlpool’s black switch-
    thermal fuse theory was undisputed or that Plaintiffs failed to produce sufficiently reliable
    evidence that the McCoy fire was ignited by the specific manufacturing defect they
    alleged. Plaintiffs presented evidence, through Mr. Martin, that manufacturing defects in
    the crimps or connectors in the door latch switch assembly could lead to excessive
    resistance heating that would reach temperatures high enough to ignite the surrounding
    plastics. Whirlpool did not challenge the scientific basis of this ignition theory, but rather
    presented countering evidence, in the form of Mr. Grunewald’s black microswitch-
    thermal fuse testimony, that excessive resistance heating could not have reached ignition
    temperatures because the black microswitches would cut off the electrical current before
    these temperatures were reached. Plaintiffs responded by pointing to Whirlpool test
    results indicating that the black microswitches did not always function as thermal fuses,6
    to evidence that fires had ignited in the door latch switch assembly area of dishwashers
    6
    This evidence consisted of both written reports by Whirlpool technicians stating
    that the microswitches had failed (melted due to excessive resistance heating) in the
    closed (electricity conducting) position during testing and evidence that several of these
    dishwashers continued operating through additional cycles even with the melted switches
    in place, something that could only occur if the switches had failed in the closed position,
    i.e., were still conducting electricity.
    13
    containing black microswitches, and to Mr. Martin’s testimony that it would be bad
    engineering science to assume that a device that was not designed to function as a thermal
    fuse reliably served this function. Although Mr. Grunewald responded with explanations
    and counter arguments in support of his opinion that the black switches always acted as
    thermal fuses and would have prevented excessive resistance heating in the door latch
    switch assembly from starting the McCoy fire, he also testified that he did not know
    whether the microswitches in the McCoy dishwasher functioned as a de facto thermal
    fuse on the night of the fire. Whether the black microswitch in the door latch switch
    assembly of the McCoy dishwasher functioned as a thermal fuse that would have
    prevented ignition was, therefore, very much disputed, and it was the jury’s province to
    decide this issue based on its assessment of the evidence and the credibility of
    Mr. Martin’s and Mr. Grunewald’s conflicting testimony.
    The district court’s reliance on Norris v. Baxter Healthcare Corp., 
    397 F.3d 878
    (10th Cir. 2005), to support its decision was also misplaced. In Norris, we found no abuse
    of discretion in the district court’s exclusion of expert witness testimony in part because it
    completely ignored or discounted without explanation a significant body of scientific
    research that had concluded there was no reliable basis for finding that the product at
    issue, silicone breast implants, caused injuries of the type suffered by the plaintiff. 
    Id. at 884-86
     (experts’ testimony “scientifically unreliable because [experts] assume what
    science has largely shown does not exist – a causal connection between silicone breast
    implants and disease.”). The record here does not demonstrate the existence of a body of
    14
    established scientific study supporting Whirlpool’s contention that the door latch switch
    assembly in the McCoy dishwasher could not have caused the McCoy fire because of the
    thermal protective properties of the black microswitches. Mr. Grunewald’s opinion in
    support of this contention is just that, an opinion, and should not have been elevated to the
    level of established scientific fact.
    II. Judgment as a Matter of Law
    The district court granted Whirlpool’s motion for judgment as a matter of law
    upon finding that Plaintiffs, even considering Mr. Martin’s testimony, had failed to
    present sufficient evidence for the jury to find that a specific manufacturing defect had
    caused the McCoy fire. McCoy, 
    379 F. Supp. 2d at 1205
    . We review de novo a district
    court’s disposition of a motion for judgment as a matter of law, applying the same legal
    standard as the district court. Snyder v. City of Moab, 
    354 F.3d 1179
    , 1184 (10th Cir.
    2003). “Such a judgment is warranted only if the evidence points but one way and is
    susceptible to no reasonable inferences supporting the party opposing the motion.” 
    Id.
    We must view the evidence and inferences to be drawn from it in the light most favorable
    to the non-moving party, Snyder, 
    354 F.3d at 1184
    , and may not weigh the evidence,
    judge witness credibility or challenge the factual conclusions of the jury, Deters v.
    Equifax Credit Info. Servs., Inc., 
    202 F.3d 1262
    , 1268 (10th Cir. 2000). In a diversity
    case such as this, the substantive law of the forum state governs our analysis of the
    underlying claims, including specification of the applicable standards of proof, but federal
    law controls the ultimate, procedural question of whether judgment as a matter of law is
    15
    appropriate. Haberman v. The Hartford Ins. Group, 
    443 F.3d 1257
    , 1264 (10th Cir.
    2006).
    Plaintiffs’ product liabilities claim is governed by Kansas law. It provides that a
    plaintiff must produce proof of three elements to present a prima facie case of strict
    product liability: (1) the injury resulted from a condition of the product; (2) the condition
    was an unreasonably dangerous one; and (3) the condition existed at the time it left the
    defendant’s control. Jenkins v. Amchem Products, Inc., 
    886 P.2d 869
    , 886 (Kan. 1994);
    Mays v. Ciba-Geigy Corp., 
    661 P.2d 348
    , 360 (Kan. 1983). “For circumstantial evidence
    to make out a prima facie case, it must tend to negate other reasonable causes, or there
    must be an expert opinion that the product was defective.” Mays, 661 P.2d at 360.
    “[T]he circumstances shown must justify an inference of probability as distinguished
    from mere possibility.” Id. The plaintiff is not required, however, “to eliminate all other
    possibilities, and so prove his case beyond a reasonable doubt. As on other issues in civil
    actions, it is enough that he makes out a preponderance of probability. It is enough that
    the court cannot say that reasonable men on the jury could not find it more likely than not
    that the fact is true.” Id. at 358 (quoting William L. Prosser, Law of Torts § 102, at 672
    (4th ed. 1971)).
    The district court vacated the jury verdict in Plaintiffs’ favor and entered judgment
    as a matter of law upon finding that Plaintiffs had failed to present sufficient evidence to
    prove that a specific defect in the McCoy’s Whirlpool dishwasher had caused the fire that
    16
    injured them.7 Reviewing the evidence in the light most favorable to Plaintiffs, and
    without weighing it or passing on the credibility of the parties’ witnesses, we must
    disagree.
    Plaintiffs presented evidence from four fire science experts, Michael J. Schultz,
    Daniel E. Anderson, Davis L. Yates and James Kuticka, who testified, based on their
    separate investigations, that the fire originated in the dishwasher in the McCoy house.8
    Three of the four further specified that the fire began in the area of the door latch switch
    assembly and that it was caused by the electrical system in this area. Plaintiffs also
    presented expert testimony from Dr. Byron Wesley Sherman, an electrical engineer, that
    his investigation of potential electrical causes of the McCoy fire had ruled out all
    potential causes except the family’s dishwasher.
    There was additional evidence in the record from both Mr. Grunewald and
    Mr. Martin that excessive resistance heating in the electrical connections in the door latch
    switch assembly of Whirlpool’s New Generation dishwashers could reach temperatures
    sufficient to ignite surrounding combustibles, and that such excessive resistance heating
    would result from a manufacturing defect in the electrical connections in the assembly.
    There was also evidence that excessive resistance heating in this area had caused fires in
    7
    There is no dispute on appeal regarding the sufficiency of Plaintiffs’ evidence on
    the other elements of its claims.
    8
    The testimony and opinions of two of these experts, David L. Yates and Daniel
    E. Anderson, was entered into the record by stipulation of the parties rather than by live
    testimony.
    17
    New Generation dishwashers that differed from the McCoy’s dishwasher only in the type
    of terminals used in the door latch switch assembly and the material from which the
    microswitches there were constructed. Plaintiffs further presented evidence, through
    Mr. Grunewald, that manufacturing defects could and had occurred in crimp connections
    in assemblies using ETCO terminals, the type present in the McCoy dishwasher, and that
    fires had actually ignited in the door latch switch assembly area of dishwashers
    containing the same black microswitches as the McCoy dishwasher. Finally, Plaintiffs
    presented expert testimony from both Mr. Martin and Mr. Grunewald that if the fire
    originated in the McCoy dishwasher’s door latch switch assembly area as opined by
    Plaintiffs’ fire experts, then it was caused by excessive resistance heating resulting from a
    defective connection in the electrical circuit in the assembly. Mr. Shultz and Mr. Kuticka,
    two of Plaintiffs’ fire origin experts, concurred that the fire originated in an abnormality
    in the assembly’s electrical circuitry.
    Viewing the totality of this evidence in the light most favorable to Plaintiffs, and
    drawing all reasonable inferences from it in the same light, there was more than sufficient
    evidence tending to negate other reasonable causes and supporting an inference of a
    defect in the electrical circuitry of the door latch switch assembly for the jury to infer, as a
    matter of probability and not mere possibility, that the fire in the McCoy home was
    caused by a manufacturing defect in the door latch switch assembly of the family’s
    Whirlpool dishwasher. Accordingly, there was sufficient evidence in the record to
    support the jury’s verdict.
    18
    The district court held otherwise and entered judgment as a matter of law in
    Whirlpool’s favor upon concluding that Plaintiffs had failed to present evidence of a
    “scientifically plausible cause” of the fire in light of Mr. Grunewald’s opinion that the
    black microswitches in the McCoy dishwasher would have prevented excessive resistance
    heating in the door latch switch assembly from reaching ignition temperatures. It was not
    Plaintiffs’ burden to disprove Mr. Grunewald’s testimony and Whirlpool’s defensive
    theory based on this testimony. “Evidence offered by [the defendant] that is contrary to
    the evidence offered by the plaintiff creates a question for the jury.” Workman v. AB
    Electrolux Corp., 
    2005 WL 1896246
     *15 (Aug. 8, 2005). As described above,
    Mr. Grunewald’s testimony was disputed, and it was the jury’s province to assess
    Mr. Grunewald’s credibility and determine the weight of his testimony. The jury was free
    to disbelieve Mr. Grunewald’s testimony, and it apparently did so.
    The district court also erred in reading Magnetek as establishing that “evidence
    that a fire originated at or within a certain product is insufficient by itself to establish that
    a product defect caused the fire.” McCoy, 
    379 F. Supp. 2d at
    1204 (citing Magnetek,
    
    360 F.3d at 1213
    ). The cited discussion in Magnetek does not state this or any other rule
    regarding the sufficiency of evidence to prove causation. Instead, the question addressed
    there was whether the expert evidence in question was reliable enough to be admitted
    under Rule 702. See 
    360 F.3d at 1211-13
     (analyzing whether the reasoning and
    methodology underlying challenged expert testimony was sufficiently reliable for
    testimony to be admitted). Whether expert evidence is admissible under Rule 702 is a
    19
    distinct and separate question from whether it and plaintiff’s other evidence is sufficient
    to prove causation or another element of the plaintiff’s claim under the governing
    substantive law. See, e.g., In re Joint E. & S. Dists. Asbestos Litig., 
    52 F.3d 1124
    , 1132
    (2nd Cir. 1995) (distinguishing between inquiry into admissibility of expert evidence and
    “[a] sufficiency inquiry, which asks whether the collective weight of a litigant’s evidence
    is adequate to present a jury question.”). Maintaining the distinction between a court’s
    reliability determination under Rule 702 and a sufficiency or merits determination is
    “indeed significant as it preserves the fact finding role of the jury.” In re TMI Litig.,
    
    193 F.3d 613
    , 665 n.90 (3rd Cir. 1999).
    Plaintiffs also presented sufficient evidence of the manufacturing defect that
    caused the McCoy fire: a defective connection in the electrical circuitry of the door latch
    switch assembly of the McCoy dishwasher. Kansas law does not require that the
    manufacturing defect be specified any more precisely than this. The district court in fact
    acknowledged as much when it held, in denying Whirlpool’s motion for summary
    judgment, that Plaintiffs’ evidence identifying the door latch switch assembly as the
    defective component of the dishwasher satisfied the legal requirement that they identify
    the product defect responsible for their injuries. Aplt. App. at 363 (Memorandum and
    Order at 14, 
    2003 WL 21554950
     *7 (D. Kan. July 8, 2003)).9
    9
    In holding that the plaintiffs presented sufficient evidence of a defect, we are not
    suggesting that Kansas law requires plaintiffs to prove a specific manufacturing defect.
    See Mays v. Ciba-Geigy Corp., 
    661 P.2d 348
    , 360 (Kan. 1983) (holding a plaintiff may
    prove a manufacturing defect caused the injury by circumstantial evidence that tends to
    eliminate causes other than a product defect). Rather, we conclude that, even if Kansas
    20
    The district court’s concern that the jury may have speculated that the fire
    originated in a defective microswitch rather than a defective connection between the flag
    terminal and the microswitch or the conductor as alleged by Plaintiffs provides no basis
    for rejecting the jury’s verdict in Plaintiffs’ favor. Even if this degree of specificity were
    required by Kansas law, Mr. Martin’s testimony and the other evidence cited above,
    considered in the light most favorable to Plaintiffs, was sufficient for the jury to infer as a
    matter of probability that the specific defect alleged by Plaintiffs was the cause of the fire.
    For the reasons stated above, the judgment of the district court is reversed. This
    action is remanded to the district court for entry of judgment on the jury’s verdict.
    Entered for the Court
    John L. Kane
    Senior District Judge
    law requires a degree of specificity, the plaintiffs presented sufficient evidence of a
    manufacturing defect in this case.
    21