Roger Murray v. S. Route Maritime Sa , 870 F.3d 915 ( 2017 )


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  •                  FOR PUBLICATION
    UNITED STATES COURT OF APPEALS
    FOR THE NINTH CIRCUIT
    ROGER MURRAY; ELISE MURRAY,              No. 14-36056
    husband and wife,
    Plaintiffs-Appellees,       D.C. No.
    2:12-cv-01854-
    v.                          RSL
    SOUTHERN ROUTE MARITIME SA, a
    Panamanian corporation; SYNERGY            OPINION
    MARITIME PVT LTD, an Indian
    corporation; APL IRELAND M/V,
    IMO number 9260914, her gear,
    appurtenances, equipment and
    furniture, in rem,
    Defendants-Appellants.
    Appeal from the United States District Court
    for the Western District of Washington
    Robert S. Lasnik, District Judge, Presiding
    Argued and Submitted May 10, 2017
    Seattle, Washington
    Filed August 31, 2017
    Before: M. Margaret McKeown, Carlos T. Bea,
    and N. Randy Smith, Circuit Judges.
    2       MURRAY V. SOUTHERN ROUTE MARITIME SA
    Opinion by Judge McKeown;
    Dissent by Judge Bea
    SUMMARY *
    Labor Law
    The panel affirmed the district court’s judgment, after a
    jury trial, in favor of the plaintiff in an action under the
    Longshore and Harbor Workers’ Compensation Act.
    While working aboard a vessel, the plaintiff, a longshore
    worker, experienced an electrical shock when a piece of
    rebar he was holding came into contact with a floodlight
    provided by the vessel owner. He alleged that the vessel
    owner had been negligent in turning over the ship with a
    faulty floodlight.
    The panel held that the district court properly instructed
    the jury that the vessel owner owed a duty to the plaintiff as
    a longshore worker to turn over the ship and its equipment
    in a reasonably safe condition, which necessarily required
    the vessel owner to take reasonable steps to inspect the ship
    and equipment before turnover.
    The panel held that the district court did not abuse its
    discretion in allowing the plaintiff’s key scientific expert to
    describe his theory of electrical injury because the court
    adequately assessed the reliability of his theory and fulfilled
    its gatekeeping function under Federal Rule of Evidence 702
    *
    This summary constitutes no part of the opinion of the court. It
    has been prepared by court staff for the convenience of the reader.
    MURRAY V. SOUTHERN ROUTE MARITIME SA                 3
    and Daubert v. Merrell Dow Pharmaceuticals, Inc., 
    509 U.S. 579
     (1993). The district court also did not err in admitting
    the medical experts’ testimony.
    Dissenting in part, Judge Bea concurred in the panel
    majority opinion’s conclusions and reasoning regarding the
    jury instructions, the scope of the defendants’ turnover duty,
    and the admission of the statements by the plaintiff’s
    medical experts.        He dissented from the majority’s
    conclusion that the district court properly admitted the
    scientific expert’s testimony. Judge Bea wrote that because
    the causal mechanism by which low voltage shocks
    purportedly cause certain injuries is not understood and
    because the district court did not evaluate the methodologies
    used by the expert to identify the posited correlation between
    low voltage shocks and certain injuries, the district court
    abused its discretion in admitting the expert’s testimony.
    COUNSEL
    Philip A. Talmadge (argued), Talmadge/Fitzpatrick/Tribe,
    Seattle, Washington; Barbara L. Holland and David H.
    Smith, Garvey Schubert Barer, Seattle, Washington; for
    Defendants-Appellants.
    Howard Mark Goodfriend (argued) and Ian C. Cairns,
    Seattle, Washington; C. Steven Fury, Francisco A. Duarte,
    and Scott D. Smith, Fury Duarte P.S., Seattle, Washington;
    for Plaintiffs-Appellees.
    4      MURRAY V. SOUTHERN ROUTE MARITIME SA
    OPINION
    McKEOWN, Circuit Judge:
    The events underlying this appeal center on Roger
    Murray, a longshoreman who experienced an electrical
    shock while working aboard the M/V APL IRELAND, a
    vessel owned by Southern Route Maritime SA and Synergy
    Maritime Pvt. Ltd. (collectively, the “vessel owner”). While
    Murray was descending a ladder and holding a piece of
    rebar, the rebar came into contact with a floodlight provided
    by the vessel owner which allowed electrical current to flow
    through his right arm, across his chest, and out through his
    left pinky, where it left a visible burn mark. Murray
    exhibited a range of ailments after the shock, including
    stuttering, balance and gait problems, and erectile
    dysfunction.
    Murray sued under the Longshore and Harbor Workers’
    Compensation Act (“Longshore Act”), 
    33 U.S.C. § 901
     et
    seq., alleging that the vessel owner had been negligent in
    turning over the ship with a faulty floodlight. The jury
    awarded Murray over $3.3 million for his injuries and
    awarded his wife $270,000 for loss of consortium. The
    district court denied the vessel owner’s motions for
    judgment as a matter of law, new trial, and remittitur.
    Unwilling to go down with the ship, the vessel owner
    appeals, asserting three trial errors—a flawed jury
    instruction and two errors related to the admission of
    testimony by Murray’s experts. We disagree on all counts.
    The district court properly instructed the jury that the vessel
    owner owes a duty to Murray as a longshoreman to turn over
    the ship and its equipment in a reasonably safe condition,
    which necessarily requires the vessel owner to take
    reasonable steps to inspect the ship and equipment before
    MURRAY V. SOUTHERN ROUTE MARITIME SA                 5
    turnover. Further, the court did not abuse its discretion in
    allowing Murray’s key scientific expert to describe his
    theory of electrical injury because the court adequately
    assessed the reliability of his theory and fulfilled its
    gatekeeping function under Federal Rule of Evidence 702
    and Daubert v. Merrell Dow Pharmaceuticals, Inc., 
    509 U.S. 579
     (1993). Likewise, there was no error in admitting the
    medical experts’ testimony. We affirm.
    Analysis
    I. Jury Instruction Defining the Turnover Duty
    Under the Longshore Act
    The Longshore Act provides a cause of action to
    longshoremen against the vessel owner “[i]n the event of
    injury . . . caused by the negligence of a vessel.” 
    33 U.S.C. § 905
    (b). Here, Murray claims that the vessel owner
    breached its duty to turn over the vessel and its equipment in
    a safe condition.
    At issue is Instruction 14, in which the district court
    defined the vessel owner’s turnover duty:
    One of the duties [vessel owners] owe to
    longshoremen is called “the turnover duty of
    safe condition.” [The vessel owner] ha[s] the
    duty to use reasonable care to turn over the
    vessel and its equipment in such condition
    that an expert and experienced longshoreman
    would be able, by the exercise of reasonable
    care, to carry on his work on the vessel with
    reasonable safety to persons and property. In
    exercising such reasonable care, [the vessel
    owner] ha[s] a duty to take reasonable steps
    to inspect the vessel and its equipment.
    6      MURRAY V. SOUTHERN ROUTE MARITIME SA
    The first sentence is introductory. The second sentence
    captures almost word-for-word the Supreme Court’s general
    description of the turnover duty:
    A vessel [owner] must exercise ordinary care
    under the circumstances to turn over the ship
    and its equipment and appliances in such
    condition that an expert and experienced
    stevedoring contractor, mindful of the
    dangers he should reasonably expect to
    encounter, arising from the hazards of the
    ship’s service or otherwise, will be able by
    the exercise of ordinary care to carry on cargo
    operations with reasonable safety to persons
    and property.
    Howlett v. Birkdale Shipping Co., S.A., 
    512 U.S. 92
    , 98
    (1994) (citation and internal quotation marks omitted);
    Scindia Steam Navigation Co. v. De Los Santos, 
    451 U.S. 156
    , 166–67 (1981). The third sentence of the instruction
    gives practical meaning to the turnover duty by recognizing
    a duty to inspect the ship and equipment.
    In the vessel owner’s view, Instruction 14’s formulation
    of the turnover duty is legally flawed because the instruction
    improperly expands the vessel owner’s obligation to inspect
    the ship and equipment, states that the duty is to the
    longshoremen rather than the stevedoring company, and
    imposes an ongoing duty to inspect. Reviewing de novo, we
    conclude that the district court did not commit instructional
    error. See Image Tech. Servs., Inc. v. Eastman Kodak Co.,
    
    125 F.3d 1195
    , 1208 (9th Cir. 1997).
    MURRAY V. SOUTHERN ROUTE MARITIME SA                   7
    A. Turnover Duty Encompasses Duty to Inspect
    The Supreme Court’s first major exposition on the
    turnover duty under § 905(b) came in Scindia Steam, which
    contemplates a duty to inspect as part and parcel of the
    turnover duty. Although a duty to inspect is not mentioned
    explicitly, the Court defined the vessel owner’s “duty with
    respect to the condition of the ship’s gear, equipment, tools,
    and work space to be used in the stevedoring operations.”
    Scindia Steam, 
    451 U.S. at 167
    . To that end, a vessel owner
    fulfills its responsibilities when it provides a reasonably safe
    workplace for the longshoremen. 
    Id.
     at 166–67. The only
    way the vessel owner can do so is by checking the ship and
    equipment before turning them over in order to confirm that
    they are safe enough to be used in cargo operations.
    Otherwise, the turnover duty would be rendered nugatory,
    taking on a “see no evil” approach.
    As one treatise puts it, Scindia Steam “implicate[s] the
    shipowner’s duty to inspect the ship for hazards before
    turning the ship over . . . because inspection is integral to
    providing the stevedore with a reasonably safe workplace.”
    Robert Force & Martin J. Norris, The Law of Maritime
    Personal Injuries § 8:30 (5th ed. 2016). Justice Brennan’s
    concurrence in Scindia Steam reads the majority opinion the
    same way, explaining that the law requires a vessel owner to
    “take reasonable steps to determine whether the ship’s
    equipment is safe before turning that equipment over to the
    stevedore.” 
    451 U.S. at 179
     (Brennan, J., concurring).
    The Court’s later pronouncements on the turnover duty
    reinforce the inspection obligation. After reiterating a vessel
    owner’s general turnover duty, the Court in Howlett
    examined the “corollary” duty to warn the stevedore of latent
    hazards that are known or should be known to the vessel
    owner. 
    512 U.S. at
    98–99. The Court went on to conclude
    8      MURRAY V. SOUTHERN ROUTE MARITIME SA
    that the duty to warn attaches where “the exercise of
    reasonable care would place upon the shipowner an
    obligation to inspect for, or discover, the hazard’s
    existence.” 
    Id. at 100
    . In explaining the relationship
    between the duty to warn and the inspection duty, the Court
    cited a Third Circuit case for the proposition that “the
    shipowner’s duty to warn the stevedore of hidden dangers
    necessarily implies a duty to inspect to discover those
    dangers.” Kirsch v. Plovidba, 
    971 F.2d 1026
    , 1029 (3d Cir.
    1992), cited in Howlett, 
    512 U.S. at 100
    . Howlett more than
    suggests that reasonable steps be taken to inspect the ship
    and equipment before turnover.
    Our court has been even clearer on a vessel owner’s duty
    to perform an inspection to fulfill its turnover duty. We have
    unequivocally held that “[w]here the shipowner itself
    supplies equipment, it has a duty to inspect the equipment
    before turning it over for use by the stevedore.” Hedrick v.
    Daiko Shoji Co., 
    715 F.2d 1355
    , 1357 (9th Cir. 1983); see
    also Lincoln v. Reksten Mgmt., 
    354 F.3d 262
    , 268 (4th Cir.
    2003) (“[T]he vessel might have been negligent in the
    maintenance, upkeep, and especially the inspection of the
    deck in question, so that, in the exercise of reasonable care,
    it might have discovered the defect . . . , enabling it to warn
    the stevedore of the defect.” (emphasis added)); Reed v. ULS
    Corp., 
    178 F.3d 988
    , 992 (8th Cir. 1999) (affirming
    summary judgment for vessel owner because “[t]he record
    reflects that the inspection of the gangway . . . was
    reasonable”); Kirsch, 
    971 F.2d at 1029
     (noting “the
    shipowner’s duty to inspect the ship for hazards before
    turning the ship over to the stevedore”).
    This formulation of the turnover duty produces doctrinal
    coherence because it logically fits the duty to inspect within
    the general turnover duty and its corollary duty to warn. The
    MURRAY V. SOUTHERN ROUTE MARITIME SA                   9
    turnover duty mandates exercising reasonable care to
    provide a ship and equipment that are reasonably safe for the
    stevedore to carry on cargo operations. Part of that duty is
    to examine the ship and equipment. When that inspection
    turns up latent hazards that would not be obvious to or
    anticipated by a competent stevedore, the vessel owner’s
    duty to warn kicks in because the vessel owner is in the best
    position to detect and avoid harm and should be liable if it
    does not speak up. See Howlett, 
    512 U.S. at
    101–03. The
    vessel owner’s belated argument to limit the inspection to
    identifying latent hazards would dilute the turnover duty
    envisioned by the case law and would be unworkable in
    practice.
    Recognizing a duty to inspect as part of the turnover duty
    does not expand shipowner liability. The inspection is
    constrained by what is reasonable under the circumstances,
    and the ultimate measure of whether the vessel owner has
    satisfied its turnover duty is whether the vessel owner has
    provided a reasonably safe environment for the
    longshoremen to carry out their work. The limited nature of
    the duty undercuts the vessel owner’s fear that it will be
    obligated to scour every inch of the vessel and tear apart all
    of the equipment.          Because the inquiry turns on
    reasonableness, our rule also does not resurrect the strict-
    liability unseaworthiness regime that Congress dismantled
    by passing § 905(b). See Scindia Steam, 
    451 U.S. at
    168–
    69. The duty to inspect falls comfortably within the turnover
    duty, and the district court’s instructional clarifier was on the
    mark.
    B. Turnover Duty Runs to the Longshoremen
    The vessel owner’s complaint that Instruction 14
    improperly states that the turnover duty is “owe[d] to
    longshoremen” was not adequately raised in the district
    10     MURRAY V. SOUTHERN ROUTE MARITIME SA
    court. Granted, the vessel owner’s counsel objected to
    another instruction on this ground and proposed an
    instruction regarding the stevedoring company’s duties to
    the longshoremen. However, those efforts did not raise the
    objection to Instruction 14 with sufficient specificity to
    “bring into focus the precise nature of the alleged error.”
    Palmer v. Hoffman, 
    318 U.S. 109
    , 119 (1943); see also Fed.
    R. Civ. P. 51(c)(1). At a minimum, the vessel owner would
    have to demonstrate plain error in the instruction to warrant
    reversal. See Fed. R. Civ. P. 51(d)(2).
    The vessel owner cannot make that showing because the
    law supports the proposition that vessel owners owe the
    turnover duty to the longshoremen. The relevant statute,
    § 905(b), speaks of “injury to a person covered under this
    chapter,” which includes longshoremen. See 
    33 U.S.C. §§ 902
    (1), (3); 905(b). The two leading Supreme Court
    cases involve suits brought by longshoremen against vessel
    owners and say that “the vessel owes to the stevedore and
    his longshoremen employees the duty of exercising due
    care.” Scindia Steam, 
    451 U.S. at 166
    ; see Howlett, 
    512 U.S. at 98
     (outlining the “three general duties shipowners owe to
    longshoremen”). We have framed the inquiry in the same
    way: “Although the turnover duty of safe condition is
    usually framed in terms of stevedores, it is clear that danger
    to longshore workers is an essential part of the inquiry.”
    Thomas v. Newton Int’l Enters., 
    42 F.3d 1266
    , 1270 n.4 (9th
    Cir. 1994).
    The stevedoring company’s separate obligation under
    
    33 U.S.C. § 941
    (a) to provide a “reasonably safe” workplace
    for its longshoremen does not somehow override the vessel
    owner’s duty to the longshoremen to turn over the ship and
    equipment in a safe condition. Those duties happily coexist,
    with the vessel owner ensuring a safe ship upon turnover and
    MURRAY V. SOUTHERN ROUTE MARITIME SA                 11
    the stevedoring company ensuring a safe work environment
    during cargo operations. See Scindia Steam, 
    451 U.S. at
    170–72. The district court properly instructed the jury on the
    vessel owner’s turnover duty to longshoremen.
    C. Turnover Duty Is Not Continuing
    The vessel owner also did not put the district court on
    notice about its complaint that Instruction 14 creates a
    temporally unrestricted duty to inspect and leaves the vessel
    owner open to a virtually unlimited obligation. See Benigni
    v. City of Hemet, 
    879 F.2d 473
    , 475–76 (9th Cir. 1988)
    (noting that “the record indicates that the trial court was not
    made aware of any specific concern with the proposed
    instructions”). In any event, regardless of the standard of
    review, the vessel owner’s challenge cannot be sustained
    because Instruction 14 plainly refers to the moment of
    turnover and not to a perpetual duty, and other instructions
    confirm that limitation.
    Instruction 14 itself refers to the vessel owner’s duty
    when it “turn[s] over the vessel and its equipment.”
    Looking at the surrounding instructions, Instruction 12
    summarizes Murray’s theory of the case “that [the vessel
    owner was] negligent because the vessel and its equipment
    were not turned over in a [safe] condition.” And Instruction
    13, which sets forth the elements of Murray’s negligence
    claim, states that liability cannot be found unless the vessel
    owner “turned over the [vessel] and its equipment in [an
    unsafe] condition.” These related instructions make clear
    that the district court did not charge a continuing post-
    turnover duty.
    12      MURRAY V. SOUTHERN ROUTE MARITIME SA
    II. Reliability of Dr. Morse’s Testimony Under
    Daubert
    The district court admitted Murray’s scientific expert,
    Dr. Michael Morse, who testified that low-voltage shock can
    cause bodily injuries far from the path of the electrical
    current. Following a hearing, the court issued an order
    detailing why Dr. Morse’s diffuse electrical injury theory
    was reliable under Federal Rule of Evidence 702 and
    Daubert. We review for abuse of discretion and conclude
    that the court performed a sufficiently rigorous evaluation of
    Dr. Morse’s theory and did not “reach[] a result that is
    illogical, implausible, or without support in inferences that
    may be drawn from the record.” United States v. Hinkson,
    
    585 F.3d 1247
    , 1262 (9th Cir. 2009) (en banc).
    The starting point for our analysis is the Supreme Court’s
    decision in Daubert, a case that effected a sea change in the
    way that courts consider admission of expert testimony.
    Before Daubert, courts generally followed the “general
    acceptance” test, which focused on recognition in the
    relevant field. 
    509 U.S. at
    585–86. The Court in Daubert
    rejected that test as too rigid; drawing on Federal Rule of
    Evidence 702, the Court constructed a flexible test
    examining the “reliability” and “fit” of the offered expert
    testimony. See 
    id.
     at 589–92.
    The question of reliability probes “whether the reasoning
    or methodology underlying the testimony is scientifically
    valid.” 
    Id.
     at 592–93. To give shape to the inquiry, the Court
    identified four factors that may bear on the analysis:
    (1) whether the theory can be and has been tested,
    (2) whether the theory has been peer reviewed and
    published, (3) what the theory’s known or potential error rate
    is, and (4) whether the theory enjoys general acceptance in
    the applicable scientific community. See 
    id.
     at 593–94. But
    MURRAY V. SOUTHERN ROUTE MARITIME SA                  13
    the Court was quick to emphasize that the factors are not “a
    definitive checklist or test” and that the reliability analysis
    remains a malleable one tied to the facts of each case. 
    Id. at 591, 593
    . Later cases have reiterated that the Daubert
    factors are exemplary, not constraining. Kumho Tire Co. v.
    Carmichael, 
    526 U.S. 137
    , 150 (1999); 
    id. at 159
     (Scalia, J.,
    concurring) (“[T]he Daubert factors are not holy writ . . . .”).
    It is important to remember that the factors are not
    “equally applicable (or applicable at all) in every case.”
    Daubert v. Merrell Dow Pharm., Inc., 
    43 F.3d 1311
    , 1317
    (9th Cir. 1995). Applicability “depend[s] on the nature of
    the issue, the expert’s particular expertise, and the subject of
    his testimony.” Kumho Tire Co., 
    526 U.S. at 150
     (citation
    omitted). A district court may permissibly choose not to
    examine factors that are not “reasonable measures of
    reliability in a particular case.” 
    Id. at 153
    .
    Because of the fluid and contextual nature of the inquiry,
    district courts are vested with “broad latitude” to “decid[e]
    how to test an expert’s reliability” and “whether or not [an]
    expert’s relevant testimony is reliable.” 
    Id.
     at 152–53.
    District judges play an active and important role as
    gatekeepers examining the full picture of the experts’
    methodology and preventing shoddy expert testimony and
    junk science from reaching the jury. See Daubert, 
    509 U.S. at
    595–97. That is why we owe the court’s ruling “the
    deference that is the hallmark of abuse-of-discretion review”
    and may not second-guess its sound judgments. Gen. Elec.
    Co. v. Joiner, 
    522 U.S. 136
    , 141–43 (1997).
    The court did not abuse its discretion here because its
    reliability inquiry satisfies these standards and the court
    applied the correct legal framework to the facts in a manner
    that was neither illogical nor implausible nor contrary to the
    record. In its Daubert order, the court first explains that Dr.
    14      MURRAY V. SOUTHERN ROUTE MARITIME SA
    Morse “has published his findings in peer-reviewed papers.”
    “[S]ubmission to the scrutiny of the scientific community”
    can be a strong indicator of reliability “because it increases
    the likelihood that substantive flaws in methodology will be
    detected.” Daubert, 
    509 U.S. at 593
    . Dr. Morse’s theory
    has been peer-reviewed and published many times over:
    Murray’s filings in the district court cite eight articles by Dr.
    Morse published in reputable scientific journals. More
    generally, Murray submitted a wealth of examples of other
    scientists publishing in peer-reviewed journals on the theory
    of low-voltage and diffuse electrical injury.
    The court then discusses acceptance of Dr. Morse’s
    theory by other professionals in the biomedical engineering
    field. The court was on solid ground in rejecting the vessel
    owner’s contention that “the number of confirmed low-
    voltage cases is too small to draw scientifically valid
    conclusions and that the minimum voltage required to cause
    injury has not yet been established with any degree of
    certainty.” Relying on the record, the court specifically
    credited Dr. Morse’s response that “over the past two
    decades both the immediate and extended symptomology of
    low-voltage shock has been recognized,” an observation
    grounded in his expertise in electrical injury and years of
    research in the field. Also, the record is replete with
    examples of articles that explicitly agree with Dr. Morse’s
    theory and methodology as well as articles that cite to and
    expand on his conclusions. Even if the vessel owner
    presented medical sources disagreeing with Dr. Morse, the
    district court could properly give weight to the fact that Dr.
    Morse’s theory has been acknowledged and credited by
    scientists in the community without determining the exact
    degree of acceptance. See 
    id. at 594
    .
    MURRAY V. SOUTHERN ROUTE MARITIME SA                15
    The court’s analysis does not end there. It evaluates the
    genesis of the expert opinion, a factor recognized in the
    advisory notes and our case law: Dr. Morse’s theory “w[as]
    not developed for purposes of this litigation.” See Fed. R.
    Evid. 702 advisory committee’s note to the 2000
    amendments; Daubert, 
    43 F.3d at 1317
    . Importantly, our
    cases call this consideration a “very significant fact” that
    “provides important, objective proof that the research
    comports with the dictates of good science.” Daubert,
    
    43 F.3d at 1317
    . The order also goes on to say that “[Dr.
    Morse’s] conclusions are reasonable extrapolations from the
    patient files reviewed,” tracking another known factor. See
    Joiner, 
    522 U.S. at 146
     (“A court may conclude that there is
    simply too great an analytical gap between the data and the
    opinion proffered.”); see also Fed. R. Evid. 702 advisory
    committee’s note to the 2000 amendments (listing
    “[w]hether the expert has unjustifiably extrapolated from an
    accepted premise to an unfounded conclusion”). Based on
    these multiple considerations, the district court concluded
    that Dr. Morse’s theory was grounded in science, as
    demanded by Daubert. See 
    509 U.S. at 594
     (explaining that
    the “overarching subject is the scientific validity”).
    The adequacy of the court’s review and the soundness of
    its judgment are further underscored by its discretionary
    decision to convene a Daubert hearing to explore matters
    with the parties. See United States v. Alatorre, 
    222 F.3d 1098
    , 1102, 1105 (9th Cir. 2000). At the hearing, the district
    judge played a proactive role: he was eager to receive
    information from the parties, asking them to submit all
    relevant articles and stating that he would “look[] at the
    entire body of the case, every document that has been filed
    beforehand, and every document that’s filed in this motion
    and response.” He gave the attorneys the opportunity to
    debate the issues and actively questioned them about the
    16      MURRAY V. SOUTHERN ROUTE MARITIME SA
    strengths and weaknesses of their positions. Only after this
    extensive back-and-forth and consideration of the parties’
    papers did the court issue its order admitting Dr. Morse’s
    testimony.
    It is true that the order does not scrutinize the testability
    and error rate factors. Although Daubert does not require a
    methodical walkthrough of each factor, the best practice may
    be for district courts to at least reference the four Daubert
    factors so as to avoid an appeal issue like the one here. See
    Black v. Food Lion, Inc., 
    171 F.3d 308
    , 311–12 (5th Cir.
    1999) (“In the vast majority of cases, the district court first
    should decide whether the factors mentioned in Daubert are
    appropriate. Once it considers the Daubert factors, the court
    then can consider . . . other factors . . . .”). That said, we
    emphasize that not every factor is relevant to reliability in
    every case and that the significance of each factor is case-
    dependent. District courts have broad range to structure the
    reliability inquiry and may choose not to comment on factors
    that would not inform the analysis.
    The district court’s silence about the testability and error
    rate factors falls within that broad discretion. The omission
    may be attributed in part to the parties’ nearly exclusive
    concentration on the other two factors—peer review and
    general acceptance. Those issues were teased out at length
    in the parties’ motions and at the Daubert hearing, and thus
    the court put them front and center in its order assessing Dr.
    Morse’s testimony.
    Even more forcefully, the district court’s order
    highlighted that the subject of Dr. Morse’s testimony was
    narrow: he would discuss his theory of low-voltage diffuse
    electrical injury, but he would not offer an opinion on
    whether Murray’s particular injuries were caused by the low-
    voltage shock. That limited focus made many of the vessel
    MURRAY V. SOUTHERN ROUTE MARITIME SA                17
    owner’s critiques on testability misplaced and made the error
    rate a poor measure of reliability in this case. See Kumho
    Tire Co., 
    526 U.S. at 153
     (permitting district courts to
    discount factors that are not “reasonable measures of
    reliability in [the] particular case”). And to the extent that
    testability was raised before the district court, it was not
    forgotten or wholly ignored—the parties and district judge
    spent time at the Daubert hearing exploring whether Dr.
    Morse had followed a modified methodology drawn from
    one of his published papers. All of this convinces us that the
    district court fulfilled its gatekeeping role and did not jump
    to a conclusion that is unreasonable or unsupported by
    record evidence.
    Our view that the district court acted well within its
    discretion is in accord with how we have treated other
    Daubert challenges. On many occasions, we have found an
    abuse of discretion when a district court completely
    abdicates its gatekeeping role. See, e.g., City of Pomona v.
    SQM N. Am. Corp., No. 15-56062, 
    2017 WL 3378770
    , at *7
    (9th Cir. Aug. 7, 2017) (explaining that the district court’s
    “failure to make any findings regarding the efficacy of [the]
    expert opinions constituted an abdication of the district
    court’s gatekeeping role, and necessarily an abuse of
    discretion”); Pyramid Techs., Inc. v. Hartford Cas. Ins. Co.,
    
    752 F.3d 807
    , 814 (9th Cir. 2014) (faulting the district court
    for “provid[ing] no explanation or analysis for rejecting [the
    expert’s] qualifications”); Estate of Barabin v.
    AstenJohnson, Inc., 
    740 F.3d 457
    , 464 (9th Cir. 2014) (en
    banc) (“[T]he district court failed to assume its role as
    gatekeeper with respect to [the expert’s] testimony.”);
    United States v. Vallejo, 
    237 F.3d 1008
    , 1019 (9th Cir. 2001)
    (“The district court never clearly articulated why it excluded
    this evidence.”). Other times, the analytical error has been
    egregious, like when a court would not let a highly qualified
    18     MURRAY V. SOUTHERN ROUTE MARITIME SA
    and experienced doctor comment that prosthetic elbows
    normally do not wear out in eight months. See Primiano v.
    Cook, 
    598 F.3d 558
    , 562–63, 566 (9th Cir. 2010). In rare
    instances, we have even faulted district courts for being too
    robotic in applying Daubert.              See Wendell v.
    GlaxoSmithKline LLC, 
    858 F.3d 1227
    , 1233 (9th Cir. 2017)
    (“The district court looked too narrowly at each individual
    consideration, without taking into account the broader
    picture of the experts’ overall methodology.”). None of
    those circumstances is applicable here.
    At the end of the day, the appropriate way to discredit
    Dr. Morse’s theory was through competing evidence and
    incisive cross-examination. See Primiano, 
    598 F.3d at 564
    (“Shaky but admissible evidence is to be attacked by cross
    examination, contrary evidence, and attention to the burden
    of proof, not exclusion.”). Indeed, many of the vessel
    owner’s complaints focus on statements made by Dr. Morse
    at trial. The best medicine was adversarial testing, not
    exclusion, and the vessel owner had abundant opportunity to
    undermine Dr. Morse’s theory and advance its own position.
    We decline the invitation to severely curtail district courts’
    discretion to determine reliability under Daubert merely
    because the vessel owner’s defense was unsuccessful.
    III.    Admission of Medical Experts
    The district court had a proper basis to admit Murray’s
    medical experts, who testified that Murray’s symptoms were
    caused by the electrical shock. The vessel owner’s claim
    that the experts did not testify on a more-probable-than-not
    basis is belied by the record. Before trial, Murray’s experts
    confirmed their medical opinion to a reasonable degree of
    certainty on a more-probable-than-not basis. And, at trial,
    there were numerous instances in which the experts testified
    in the same fashion. For example, one of the experts
    MURRAY V. SOUTHERN ROUTE MARITIME SA                19
    explicitly referenced the relevant standard in attesting that
    “[i]t’s my opinion that on a more probable than not basis
    [Murray] suffered a brain injury in the accident” and “that
    [the brain injury] relate[d] directly to th[e] incident [where
    he was electrocuted].”
    Similarly, Murray’s experts properly followed the
    differential diagnosis framework. Differential diagnosis is
    appropriate to reject alternative causes where it is “grounded
    in significant clinical experience and examination of medical
    records and literature.” Messick v. Novartis Pharm. Corp.,
    
    747 F.3d 1193
    , 1199 (9th Cir. 2014). Here, the experts who
    did not have experience with diffuse electrical injury
    reviewed the medical literature. The experts fully explained
    how Murray’s symptoms fit with the literature or their
    experience and were not pre-existing or unrelated to the
    shock. The district court did not abuse its discretion in
    admitting the medical testimony.
    AFFIRMED.
    BEA, Circuit Judge, dissenting in part:
    I concur in the panel majority opinion’s conclusions and
    reasoning regarding the jury instructions, the scope of the
    defendants’ turnover duty, and the admission of the
    statements by Murray’s medical experts. I write separately
    to dissent on the issue of whether the district court properly
    admitted the testimony of Dr. Morse regarding the harms
    that can be caused by low voltage electric shocks. Put
    simply, the district court failed to exercise properly its
    gatekeeping function by permitting Dr. Morse’s testimony
    without examining the methodologies by which Dr. Morse
    identified the injuries purportedly caused by low voltage
    20     MURRAY V. SOUTHERN ROUTE MARITIME SA
    shocks, even though Dr. Morse could not explain the causal
    mechanism by which such injuries occur.
    As explained in Daubert v. Merrell Dow
    Pharmaceuticals, Inc., 
    509 U.S. 579
    , 591–93 (1993), which
    interpreted Federal Rule of Evidence 702, the touchstone for
    admissibility of testimony by scientific experts is “whether
    the reasoning or methodology underlying the testimony is
    scientifically valid.” Given the many ways that scientific
    expertise is developed and applied, however, the Supreme
    Court and this court have recognized that the four factors
    articulated in Daubert do not constitute a mandatory
    checklist. 
    Id.
     at 593–95. Rather, each factor should be
    addressed to the extent relevant to a particular expert’s
    testimony. Id.; see also Kumho Tire Co. v. Carmichael,
    
    526 U.S. 137
    , 153 (1999), Daubert v. Merrell Dow
    Pharmaceuticals, Inc., 
    43 F.3d 1311
    , 1317 (9th Cir. 1995).
    While an appeals court may not second guess the sound
    judgment of the district court on the admissibility of expert
    testimony, Gen. Elec. Co. v. Joiner, 
    522 U.S. 136
    , 146
    (1997), the unreasonable failure to consider a relevant
    Daubert factor is an abuse of discretion. See Kumho Tire,
    
    526 U.S. at 152
    .
    In this case, the district court evaluated only two of the
    relevant Daubert factors: whether the expert’s research was
    peer reviewed and whether it was generally accepted by
    other scholars. The district court failed to consider whether
    Dr. Morse’s theory can be and has been tested and the error
    rate associated with the methodologies he relied upon to
    render his opinion. The district court did not offer any
    reasons as to why it overlooked these two factors.
    First, the relevance of Dr. Morse’s testimony to Murray’s
    injuries is unclear. Dr. Morse testified that Murray’s
    symptoms were consistent with the low voltage shocks he
    MURRAY V. SOUTHERN ROUTE MARITIME SA                 21
    had studied, but Dr. Morse’s expert report discusses low-
    voltage shocks as being those of 110 volts. This was roughly
    twice the voltage of the shock experienced by Murray, which
    was somewhere between 41 and 58 volts. Expert testimony
    should not be admitted if it is not relevant, which this court
    has defined as evidence that “logically advance[s] a material
    aspect of [a] party’s case.”          Estate of Barabin v.
    AstenJohnson, Inc., 
    740 F.3d 457
    , 463 (9th Cir. 2014)
    (citation omitted). In this case, the definition of “low
    voltage” relied upon by Dr. Morse (110 volts) differed
    significantly from the “low voltage” shock suffered by
    Murray (41–58 volts). Such a difference raises serious
    doubts about the relevance to Murray’s injuries of Dr.
    Morse’s expertise, a doubt which the district court failed to
    address in its Daubert order. The district court failed to cite
    any record evidence that would allow Dr. Morse’s findings
    regarding 110 volt shocks to be extrapolated to the lower
    voltage shock experienced by Murray.
    Second, the district court does not explain why the
    Daubert factors of testability and error rate were not relevant
    to evaluating the admissibility of Dr. Morse’s expert
    testimony. As Dr. Morse conceded, the mechanism by
    which the hypothesized injuries resulting from low voltage
    shocks occur is not understood. Such an admission should
    reasonably have led the district court to apply greater
    scrutiny to the methodology by which Dr. Morse arrived at
    his hypothesis about diffuse injury from low voltage shock.
    If the mechanism for an injury is not understood, it is that
    much more important to ensure the reliability of the methods
    by which a correlation between low voltage shocks and
    certain injuries was identified. Instead, the district court
    ignored the exact Daubert factors that evaluate the rigor of
    these methodologies. Namely, the district court failed to
    evaluate whether the theory or technique in question “can be
    22     MURRAY V. SOUTHERN ROUTE MARITIME SA
    (and has been) tested.” Daubert, 
    509 U.S. at 593
    . While Dr.
    Morse’s hypothesis that low voltage shocks cause certain
    injuries can be tested, the record evidence does not establish
    that Dr. Morse’s theory was tested either through animal
    testing or other controlled experiments. Even if Dr. Morse
    is correct that low voltage shocks cause injury, this record
    does not establish whether such injuries are commonplace or
    extremely rare results of low voltage shock. In addition, the
    error rate of the particular research methodologies employed
    by Dr. Morse to identify the relationship between low
    voltage shocks and certain injuries was not addressed by the
    district court. For example, Dr. Morse relies in part on self-
    reported internet surveys of people who purportedly suffered
    a low voltage shock. See Michael S. Morse et al., Diffuse
    Electrical Injury: A Study of 89 Subjects Reporting Long-
    Term Symptomatology that Is Remote to the Theoretical
    Current Pathway, 51 IEEE Transaction on Biomedical
    Engineering 1449 (2004). By not considering the error rate
    of such self-reported surveys, the district court ignored the
    degree to which the survey respondents may have made up
    or imagined their symptoms, may not have actually received
    a low voltage electric shock, may have exaggerated their
    symptoms, or may have misunderstood the questions posed
    in the survey.
    Taken together, the fact that Dr. Morse could not explain
    the causal mechanism behind the hypothesized relationship
    between low voltage shocks and certain injuries means that
    the Daubert factors that address the reliability of the
    methods – such as error rate and testability – used to identify
    this correlation had special importance in this case. By
    ignoring these factors, without stating a reasonable basis for
    such omissions, the district court’s Daubert analysis in fact
    merely evaluated the general acceptance of Dr. Morse’s
    theories as demonstrated through certain peer reviewed
    MURRAY V. SOUTHERN ROUTE MARITIME SA                  23
    articles (functionally the same as the Frye test rejected in
    Daubert) and failed to evaluate the methodologies
    underlying Dr. Morse’s opinion. This was an abuse of
    discretion in its gate-keeping function which the deference
    owed cannot overcome.
    Finally, there are important problems with the analysis
    performed by the district court of Daubert factors of peer
    review and general acceptance. First, while the district court
    placed a great deal of weight on the fact that Dr. Morse’s
    research on low voltage shocks had been subject to peer
    review, the Supreme Court has explained that the peer
    review factor is not alone dispositive and even if an expert’s
    research is peer reviewed, a district court must still ensure
    that the expert’s opinion is based on a reliable methodology.
    Daubert, 
    509 U.S. at 594
     (“[t]he fact of publication (or lack
    thereof) in a peer reviewed journal thus will be a relevant,
    though not dispositive, consideration”). Moreover, while
    the scientific literature in the record does establish that some
    experts accepted Dr. Morse’s theories, the record makes
    clear that this acceptance did not rise to the level of general
    acceptance as a number of scientists criticized Dr. Morse’s
    theory as controversial or not persuasive, in part because, as
    discussed above, the mechanism by which injuries from low
    voltage shocks purportedly occur is not understood. See
    Daubert, 
    509 U.S. at 594
     (“a known technique which has
    been able to attract only minimal support within the
    community…may properly be viewed with skepticism”
    (citation omitted)).
    Because the causal mechanism by which low voltage
    shocks purportedly cause certain injuries is not understood
    and because the district court did not evaluate the
    methodologies used by Dr. Morse to identify the posited
    correlation between low voltage shocks and certain injuries,
    24     MURRAY V. SOUTHERN ROUTE MARITIME SA
    the district court failed to carry out its gatekeeping function.
    Barabin, 740 F.3d at 464 (“Just as the district court cannot
    abdicate its role as gatekeeper, so too must it avoid
    delegating that role to the jury.”). For these reasons, I
    respectfully dissent.