Bradley Bensenberg v. FCA US LLC ( 2022 )


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  •                                In the
    United States Court of Appeals
    For the Seventh Circuit
    No. 20-3407
    BRADLEY A. BENSENBERG,
    Executor of the Estate of
    DONNA J. BENSENBERG,
    Plaintiff-Appellant,
    v.
    FCA US LLC,
    Defendant-Appellee.
    Appeal from the United States District Court for the
    Central District of Illinois.
    No. 4:17-cv-04123 — Sara Darrow, Chief Judge.
    ARGUED SEPTEMBER 13, 2021 — DECIDED APRIL 8, 2022
    Before RIPPLE, ROVNER, and SCUDDER, Circuit Judges.
    ROVNER, Circuit Judge. Plaintiff-appellant Bradley
    Bensenberg pursues this diversity action on behalf of his
    mother’s estate seeking to recover on a claim of strict liability
    for injuries she sustained in a one-car accident in which her
    2                                                   No. 20-3407
    vehicle’s front airbag did not deploy. The district court granted
    a motion in limine to exclude the opinion of Bensenberg’s
    expert that the vehicle’s airbag was defective, in that the
    vehicle was likely traveling in excess of the deployment
    threshold for the airbag when the vehicle struck a concrete post
    and came to a halt, and yet the airbag failed to deploy. The
    flaw in the expert’s opinion, the court reasoned, was that he
    did not identify any purported defect in the vehicle’s airbag
    system but simply assumed from the airbag’s failure to deploy
    that it must have had a defect of some unspecified type. The
    court went on to enter summary judgment in favor of the
    defendant. We reverse and remand for further proceedings.
    The opinion of the plaintiff’s expert is admissible in order to
    show that the vehicle was traveling at a rate of speed sufficient
    to command deployment of the front airbag when it collided
    with the post. This in turn is sufficient to make a prima facie
    case of a non-specific defect in the vehicle’s airbag system
    within the parameters that Illinois courts have established for
    such a defect.
    I.
    On September 10, 2015, decedent Donna Bensenberg, age
    85, was driving her 2008 Chrysler Aspen (a full-sized sport
    utility vehicle) eastbound on Wolf Road, a two-lane highway,
    outside of Geneseo, Illinois (about 20 miles east of the Quad
    Cities). She lost consciousness as the result of a medical
    episode. Her car drifted across the left lane and entered a
    grassy ditch running parallel to the highway at a speed that
    witnesses (including an Illinois State Police officer) placed at
    between 45 and 65 mph. When the car encountered a raised
    earthen driveway that crossed the ditch, it became airborne
    No. 20-3407                                                    3
    and then returned to ground on the other side of the driveway,
    and eventually it came to rest upon striking a small concrete
    post. During the incident, the side-curtain airbag deployed
    when the vehicle’s sensors detected a potential roll-over, but
    the front airbag did not deploy. Ms. Bensenberg was wearing
    her seat belt, and the pretensioner (a device designed to pull
    the seat belt tight in the event of an accident) deployed
    properly. Nonetheless, there are indications that when the
    vehicle came to a halt, Ms. Bensenberg’s body came into
    contact with the steering wheel and the area of the dashboard
    beneath the steering wheel.
    As a result of the accident, Ms. Bensenberg suffered an
    undisplaced fracture of the second cervical vertebra in her
    neck. She wore a cervical collar for three months but did not
    require surgery. She died of unrelated causes three years later,
    in November 2018.
    Ms. Bensenberg filed this suit in 2017 against the car
    manufacturer, Fiat Chrysler Automotive or FCA US, formerly
    known as Chrysler Group (“Chrysler”), invoking the district
    court’s diversity jurisdiction. Following his mother’s death,
    Bensenberg stepped into her shoes as the plaintiff in his
    capacity as the personal representative of her estate. Counts I
    and II of the Fourth Amended Complaint alleged strict liability
    claims based on a manufacturing defect and a design defect,
    respectively, in the airbag system. Counts III through V alleged
    other theories of liability—strict liability for failure to warn,
    negligent failure to warn, and negligence—that are not at issue
    in this appeal. The estate also pursued claims below that the
    seatbelt system was defective, but those claims too are not
    raised on appeal.
    4                                                          No. 20-3407
    The estate retained as its expert Bahram Ravani, Ph.D., a
    Professor in Mechanical Engineering and the Graduate
    Program in Forensic Sciences and Engineering at the Univer-
    sity of California, Davis. Ravani has substantial experience and
    expertise in accident reconstruction, kinematics, and the bio-
    mechanical analysis of personal injury accidents. As relevant
    here, Ravani opined that, more likely than not, the Chrysler
    Aspen was traveling at a rate of speed closer to 53 miles per
    hour—the last speed recorded by the vehicle’s event data
    recorder (“EDR”) “black box,” which was at or near the
    moment when the vehicle’s side airbag deployed—than to five
    to 10 miles per hour (which would have been below the front
    airbag’s mandatory deployment threshold) when it struck the
    concrete post.1 Ravani’s estimate of the vehicle’s likely speed
    upon impact thus placed it above the 16 miles per hour must-
    deploy threshold for the front airbag. Ravani opined that if
    indeed the vehicle was traveling above the deployment
    threshold when it struck the post, “then the airbag system was
    defective in not deploying the airbag in such a high-energy
    impact.” R. 49-5 at 19. The airbag’s failure to deploy, Ravani
    further opined, left the driver unprotected “from contact forces
    to her body that [we]re the proximal cause of her diagnosed
    injuries.” R. 49-5 at 18. But Ravani was unable to identify any
    particular component or aspect of the airbag system, including
    1
    Ravani referenced the range of five to 10 miles per hour because he
    assumed that the deployment threshold for the front airbag of the Chrysler
    Aspen was roughly 10 miles per hour. R. 42-3 at 98. Defense witnesses,
    however, indicated that the must-deploy threshold for the Aspen’s front
    airbag was 16 miles per hour, with eight miles per hour representing a
    secondary, do-not-deploy threshold. E.g., R. 55-2 at 18.
    No. 20-3407                                                   5
    the airbag control unit (“ACU”), that he believed was defec-
    tive. (The available data from the vehicle’s airbag monitoring
    system revealed no fault in the operation of the airbag system.)
    His opinion as to the existence of a defect was instead based
    simply on the fact that the airbag did not deploy under
    circumstances in which he believed it should have deployed.
    On Chrysler’s motion, Judge Darrow excluded Ravani’s
    opinion as to the existence of a defect, which she assumed was
    a purported defect in the design of the airbag. As the judge
    understood Ravani’s reasoning, he surmised from the airbag’s
    failure to deploy at a collision speed that he placed above its
    mandatory deployment threshold that the airbag must have
    been defectively designed; but he did not articulate a theory as
    to how the design of the airbag system was defective. R. 60 at
    11. The judge did not quarrel with Ravani’s opinion that the
    impact of the vehicle likely met the deployment threshold for
    the airbag, “but rather with his jump from this premise to the
    conclusion that the airbag system was thus defective. Dr.
    Ravani offers no evidence to establish how the airbag system’s
    design was defective. … He concludes the cause from the
    effect.” R. 60 at 10.
    The court then proceeded to grant summary judgment in
    favor of Chrysler based on the lack of an expert opinion
    identifying any purported defect in the airbag system. The
    court reasoned that without expert guidance, a layperson
    would be unable to evaluate whether the airbag system was
    unreasonably dangerous as the result of a defect either in the
    design of the system or in the manufacturing process:
    6                                                    No. 20-3407
    The … airbag[ ] [is] not [a] simple product[ ].
    Although most laymen are familiar with them,
    how they work in a general sense, and what they
    aim to prevent, most laymen do not know how
    they are designed. It is not obvious what …
    airbag components are hidden from view, how
    … the systems draw information and measure it,
    how they are affected by other systems in the
    car, the type of events/forces that trigger them to
    react, etc. Expert testimony is required to help
    the trier of fact determine that an airbag …
    system, which [is a] complex product[ ], was
    unreasonably dangerous under the consumer
    expectations test or the risk-utility test due to a
    defective design or manufacturing process.
    R. 60 at 19.
    II.
    Bensenberg has made clear on appeal that he is pursuing a
    claim of manufacturing defect and has abandoned any claim of
    design defect. His theory is one of a non-specific defect in the
    airbag. For that purpose, he relies, as he did below, on expert
    opinion to show that his mother’s vehicle was likely traveling
    above the mandatory deployment threshold for the front
    airbag but that the airbag nonetheless failed to deploy. As a
    matter of Illinois law, he believes this evidence supports an
    inference that the airbag failed to deploy due to a manufactur-
    ing defect. He maintains that the district court erred in exclud-
    ing the opinion of his expert as to the existence of such a defect
    and in entering summary judgment in favor of Chrysler.
    No. 20-3407                                                         7
    The parties agree that in this diversity action we must look
    to Illinois law for the substantive legal principles governing
    Bensenberg’s claim. See Auto-Owners Ins. Co. v. Websolv
    Computing, Inc., 
    580 F.3d 543
    , 547 (7th Cir. 2009) (federal court
    hearing case in diversity looks to choice-of-law rules of forum
    state); Est. of Carey by Carey v. Hy-Temp Mfg., Inc., 
    929 F.2d 1229
    ,
    1232 (7th Cir. 1991) (under Illinois choice-of-law rules, place of
    injury supplies governing law unless another state has more
    significant relationship to occurrence or parties); Speakers of
    Sport, Inc. v. ProServ, Inc., 
    178 F.3d 862
    , 864 (7th Cir. 1999) (“The
    parties agree that the substantive issues in this diversity suit
    are governed by Illinois law, and we do not look behind such
    agreements so long as they are reasonable, as this one is.”)
    (citing Spinozzi v. ITT Sheraton Corp., 
    174 F.3d 842
    , 849 (7th Cir.
    1999)); Auto-Owners Ins. Co., 
    580 F.3d at 547
     (same).
    A strict liability claim is premised on a defect that renders
    a product dangerous because the product fails to perform in
    the manner one reasonably expects it to in light of its nature
    and intended function. Tweedy v. Wright Ford Sales, Inc., 
    357 N.E.2d 449
    , 451 (Ill. 1976); Dunham v. Vaughan & Bushnell Mfg.
    Co., 
    247 N.E.2d 401
    , 403 (Ill. 1969); Hill v. Int’l Harvester Co., 
    798 F.2d 256
    , 258 (7th Cir. 1986) (Illinois law). To prevail on such a
    claim, a plaintiff must establish each of the following elements:
    (1) a condition of the product resulting from its manufacture or
    design, (2) that made the product unreasonably dangerous,
    (3) and that existed at the time the product left the defendant’s
    control, and (4) an injury to the plaintiff, (5) that was proxi-
    mately caused by the condition. Kirk v. Clark Equip. Co., 
    991 F.3d 865
    , 878 (7th Cir. 2021) (Illinois law) (citing Clark v. River
    Metals Recycling, LLC, 
    929 F.3d 434
    , 439 (7th Cir. 2019)); see also
    8                                                     No. 20-3407
    Mikolajczyk v. Ford Motor Co., 
    901 N.E.2d 329
    , 345 (Ill. 2008). A
    product may be unreasonably dangerous as a result of (1) a
    manufacturing defect—that is, a physical defect in the individ-
    ual product itself, (2) a defect in the product’s design, or (3) the
    manufacturer’s failure to warn of a known danger associated
    with the product or to instruct the consumer on the proper use
    of the product. Mikolajczyk, 
    901 N.E.2d at 335
    ; Salerno v.
    Innovative Surveillance Tech., Inc., 
    932 N.E.2d 101
    , 108–10
    (Ill. App. Ct. 2010). A “manufacturing defect occurs when one
    unit in a product line is defective, whereas a design defect
    occurs when the specific unit conforms to the intended design
    but the intended design itself renders the product unreason-
    ably dangerous.” 
    Id. at 108
    .
    Illinois courts employ two different approaches to deter-
    mining whether a product is unreasonably dangerous: the
    consumer expectations test and the risk-utility test. Clark, 929
    F.3d at 439; Mikolajczyk, 
    901 N.E.2d at 348
    . The consumer
    expectations test asks whether the product is “dangerous to an
    extent beyond that which would be contemplated by the
    ordinary consumer who purchases it, with the ordinary
    knowledge common to the community as to its characteristics.”
    Calles v. Scripto-Tokai Corp., 
    864 N.E.2d 249
    , 255 (Ill. 2007)
    (quoting Restatement (Second) of Torts § 402A, Comment i, at
    352 (1965)). The risk-utility test balances the magnitude of the
    danger against the utility of the product, as designed. Id. at 257.
    As we have noted, Bensenberg’s theory on appeal is that a
    manufacturing defect was responsible for the failure of the
    airbag, and he invokes the consumer expectations test as the
    appropriate framework to establish that the defect rendered
    No. 20-3407                                                       9
    the airbag unreasonably dangerous. In the usual case, expert
    testimony is required to establish that a product presents an
    unreasonable danger as a result of a defect. See Show v. Ford
    Motor Co., 
    659 F.3d 584
    , 588 (7th Cir. 2011) (Illinois law); Kirk,
    991 F.3d at 878–79; R. 60 at 18. Among the expert’s tasks in
    such a case would be to identify the particular defect that gives
    rise to the danger. See, e.g., Baltus v. Weaver Div. of Kidde & Co.,
    
    557 N.E.2d 580
    , 588–90 (Ill. App. Ct. 1990). It was in this regard
    that the district court found Ravani’s opinion wanting.
    However, Illinois recognizes a claim for non-specific defect,
    which, in the appropriate case, relieves the plaintiff of the
    obligation to identify a particular defect in the product in order
    to make a prima facie case of product liability. Tweedy, 
    357 N.E.2d at 452
    ; Horne v. Elec. Eel Mfg. Co., 
    987 F.3d 704
    , 726 (7th
    Cir. 2021) (citing DiCosolo v. Janssen Pharm., Inc., 
    951 N.E.2d 1238
    , 1244 (Ill. App. Ct. 2011)); McKenzie v. S K Hand Tool Corp.,
    
    650 N.E.2d 612
    , 616 (Ill. App. Ct. 1995); Varady v. Guardian Co.,
    
    506 N.E.2d 708
    , 711–12 (Ill. App. Ct. 1987). The plaintiff may
    instead resort to circumstantial evidence that supports an
    inference that the product was defective, by showing that the
    product failed to perform as expected, in light of its nature and
    intended function, and that the product was not being used
    abnormally and that there were no reasonable secondary
    causes of failure. Tweedy, 
    357 N.E.2d at 452
    ; Horne, 987 F.3d at
    726. This is the framework that Bensenberg references on
    appeal.
    Bensenberg’s theory that there was a non-specific defect in
    the Chrysler’s airbag proceeds as follows: The front airbag was
    designed to deploy when the vehicle struck a fixed, non-
    10                                                          No. 20-3407
    deformable barrier at an impact speed of at least 16 miles per
    hour. When his mother’s vehicle left the roadway and the side
    airbag deployed, the vehicle’s EDR indicated that the vehicle
    was traveling at a rate of 53 miles per hour. Because the EDR
    stopped recording the vehicle’s speed at that point in time,
    there is no direct evidence of how fast it was traveling when it
    subsequently struck the concrete post. Based on witness
    statements and the other available data regarding the accident,
    Dr. Ravani opined that when the vehicle struck the post, it was
    likely traveling at a rate closer to 53 miles per hour than to five
    or 10 miles per hour—in other words, above the 16 miles per
    hour mandatory deployment threshold for the front airbag.
    R. 49-5 at 16–17. Yet the airbag did not deploy as one would
    expect it to have done under these circumstances.
    Before we turn to the merits of Bensenberg’s claim, we must
    deal with two preliminary objections to the claim as
    Bensenberg has framed it on appeal.
    Chrysler first contends that Bensenberg waived any theory
    of manufacturing defect by not making it below. Based on
    Ravani’s deposition, Chrysler understood Bensenberg to be
    asserting a claim of design defect only, and the district court’s
    order excluding Ravani’s opinion as to the existence of a defect
    in the airbag system and granting Chrysler’s motion for
    summary judgment indicate that its understanding was the
    same. R. 60 at 9, 11.2 However, Bensenberg’s memorandum
    2
    During Ravani’s deposition, Chrysler’s counsel pressed Ravani on
    whether he was truly comfortable asserting that the front airbag malfunc-
    tioned, given the airbag monitoring system’s failure to detect any fault in
    (continued...)
    No. 20-3407                                                                 11
    opposing summary judgment indicated that he was pursuing
    claims of both design defect and manufacturing defect. R. 49 at
    12, 19. No doubt his briefing could have been clearer on this
    point, but a close reading of his memorandum leaves no doubt
    that he was asserting a claim of manufacturing defect in
    addition to a claim of design defect. Bensenberg did not waive
    his claim of manufacturing defect.
    Chrysler also contends that Bensenberg waived his theory
    of non-specific defect and his reliance on Tweedy and its
    2
    (...continued)
    functioning of the airbag and the lack of a dashboard warning light
    signaling a problem with the airbag. R. 42-3 at 125–26. In response to
    counsel’s questioning, Ravani suggested that the airbag’s failure to deploy
    could have been attributable to a problem with the system’s design, i.e., that
    the airbag was not designed to deploy under the particular circumstances
    of this accident but that it should have been so designed. R. 42-3 at 126–30.
    Ravani did not rule out the possibility that the system was not functioning
    properly, i.e., that there was a manufacturing defect which prevented it
    from operating as designed. R. 42-3 at 130. But in view of the findings of
    Chrysler’s experts that the system was functioning properly (which defense
    counsel had highlighted in his questioning), Ravani expressed a willingness
    to take the defense experts at their word, which would leave only a design
    defect as the explanation for the airbag’s failure to deploy. R. 42-13 at 130
    (“Now, does that indicate that the air bag did not function? It could. But
    your experts have looked at it and they’re saying no, it did not [malfunc-
    tion]. The air bag is functioning properly, alright? And I take their word. So
    the air bag, assuming it is functioning properly, then the only other option is
    that the air bag is not properly designed … .”) (emphasis ours). Reading
    Ravani’s remarks in context, we do not understand him to have conceded
    away the possibility of a manufacturing defect. In any case, Ravani, as a
    witness, was not in a position to formally waive, on the plaintiff’s behalf,
    the non-specific manufacturing defect theory that Bensenberg is asserting.
    12                                                   No. 20-3407
    progeny (laying out the rationale underlying that theory) by
    failing to advance such a theory below. However, in his
    memorandum opposing summary judgment and also in his
    memorandum opposing the motion to exclude Ravani’s
    opinion, Bensenberg employed the language and logic of the
    non-specific defect cases and cited authorities discussing non-
    specific defects. R. 48 at 11, 20–21 (describing non-specific
    defect theory as “malfunction theory”); R. 49 at 21. Again, his
    two memoranda could have been clearer on this point, and it
    is true that Bensenberg did not cite the seminal Tweedy case in
    particular. But it is noteworthy that Chrysler itself cited Tweedy
    in replying to Bensenberg on the summary judgment motion.
    R. 56 at 6. So there can be no doubt that Chrysler was on notice
    that Bensenberg was advancing a non-specific defect theory.
    Bensenberg did not waive the theory of a non-specific manu-
    facturing defect in the airbag system.
    Apart from the waiver issues, Chrysler also argues that the
    non-specific defect theory articulated in Tweedy and like cases
    is inapplicable here, given the age of Bensenberg’s vehicle and
    its substantial degree of use preceding the accident. For
    purposes of addressing this argument, it is worth discussing
    Tweedy in some detail.
    In Tweedy, the brakes failed on a car that had been pur-
    chased (used but relatively new) some four months earlier and
    had only 7,500 miles on it; the driver suffered injuries as a
    result of the incident. Prior repairs had been made to the
    vehicle, but not to the brakes. The plaintiff pursued a claim of
    strict liability, but produced no expert testimony identifying
    any particular defect in the brake system of the vehicle. The
    Illinois Supreme Court nonetheless concluded that a factfinder
    No. 20-3407                                                        13
    could infer the existence of such a defect from the failure of the
    brakes to work as expected:
    Here the evidence shows that the brakes of an
    automobile driven approximately 7,500 miles,
    inspected … prior to delivery, inspected again at
    6,000 miles, and subjected to no abnormal use
    prior to the occurrence failed to function in the
    manner reasonably to be expected. Plaintiff was
    driving carefully at a reasonable rate of speed,
    the weather was good, the roads were dry, he
    knew the intersection well, and there was no
    evidence of any reasonable secondary cause.
    
    357 N.E.2d at 452
    . Consequently, it was reasonable to infer that
    the vehicle’s brakes must have been defective at the time that
    they left the seller’s control and expert testimony was not
    required in order to make out a prima facie case of a product
    defect. See 
    id.
     at 451–52.
    As Chrysler points out, subsequent cases have distin-
    guished Tweedy when the product at issue is older, has been
    subject to extensive use, and there are other apparent potential
    secondary causes of failure apart from a defect in the design or
    manufacture of the product that cannot be ruled out. See, e.g.,
    Bielskis v. Louisville Ladder, Inc., 
    663 F.3d 887
    , 899 (7th Cir. 2011)
    (distinguishing Tweedy on ground that allegedly defective
    scaffold had been in use and subject to normal wear and tear
    for a period of seven years and plaintiff had produced no
    evidence as to condition of scaffold when it came into his
    possession).
    14                                                  No. 20-3407
    The vehicle at issue here was anything but new. Bensenberg
    had purchased the Chrysler Aspen used in 2009 with about
    27,000 miles already on the odometer. By the time of the
    accident some six years later, the vehicle had accrued a total of
    roughly 128,000 miles and had been serviced and repaired
    repeatedly. On its face, this case would appear to be a far cry
    from the scenario at issue in Tweedy.
    But given the particular vehicular component at issue here,
    we are not convinced that Bensenberg was necessarily pre-
    cluded from relying on Tweedy’s articulation of the non-specific
    defect theory. Chrysler’s argument in this respect presumes
    that the reliability and efficacy of all vehicular components
    decline with time and usage of the vehicle, as is the case with
    brakes or tire treads, for example. But airbags are only used
    when deployed. Replacement will obviously be required
    following deployment, but otherwise, nothing in this record
    suggests that the lifespan of a modern airbag is shorter than
    the seven to eight years this vehicle was in use prior to the
    accident. See Ronald Montoya, Do car airbags expire?, EDMUNDS
    (Mar. 29, 2013), https://www.edmunds.com/car-safety/
    do-car-airbags-expire.html (visited April 4, 2022) (noting
    modern technology enables airbags to last for life of vehicle);
    cf. Owner’s Manual, 2008 Chrysler Aspen, at 61 (noting that
    “the airbag system is designed to be maintenance free”),
    available at https://carmanuals2.com/get/chrysler-aspen-2008-
    owner-s-manual-31277 (visited April 4, 2022). As Chrysler has
    emphasized in this litigation, vehicles including this one are
    equipped with a monitoring system that will alert the driver if
    there is a problem with the supplemental restraint system.
    Moreover, as the plaintiff points out, airbags are contained
    No. 20-3407                                                               15
    within the vehicle in such a way that makes tampering,
    modification, or inadvertent damage to the airbags difficult.
    There is no indication in the record that the airbags in this
    particular vehicle ever deployed, such that replacement was
    required, nor is there any indication the vehicle’s electronic
    monitoring system alerted Ms. Bensenberg to a potential
    malfunction or a need to service or replace the airbag system.3
    On these facts, assuming the admissibility of Ravani’s opinion
    as to the likely speed of Ms. Bensenberg’s vehicle at the time of
    impact, a jury could find that, notwithstanding the age,
    mileage, usage, and repair history of the vehicle, Ms.
    Bensenberg could reasonably expect the front airbag to deploy
    if her vehicle struck an immovable object at a rate of speed in
    excess of the airbag’s deployment threshold.
    A further word is in order here about Ravani’s opinion and
    its relationship to Bensenberg’s claim. In assessing the admissi-
    bility of Ravani’s opinion under Daubert v. Merrell Dow Pharm.,
    Inc., 
    509 U.S. 579
    , 
    113 S. Ct. 2786
     (1993), the district court
    labored under the impression that Ravani was obliged to
    3
    Our understanding of the deposition testimony of Emanuel Goodman,
    who worked for ZF Friedrichshafen AG (formerly TRW Automotive),
    which manufactures airbag control units and sensors, is that the data
    downloaded from the Chrysler Aspen’s ACU reflects a relatively compre-
    hensive history of the vehicle’s airbag system, including faults. See R. 42-5
    at 7–11, Goodman Dep. at 22–41. The data indicated that there were prior
    fault warnings for the airbag system, but not at the time of the accident. We
    may therefore assume that neither the prior ownership and use of the
    vehicle by someone other than Ms. Bensenberg nor her own extensive use
    of the vehicle cast doubt on the functionality of the airbag system, and that
    had there been a problem with the system at the time of the accident, the
    ACU data would have reflected it.
    16                                                  No. 20-3407
    identify a specific defect in the airbag system. She therefore
    viewed as ipse dixit his conclusion that the airbag system was
    defective because the front airbag did not deploy notwith-
    standing the collision with the concrete post at a speed above
    the deployment threshold for that airbag. R. 20 at 6, 10, 11. But
    this misapprehends the nature of Bensenberg’s theory of the
    case. Because Bensenberg is pursuing a claim of non-specific
    defect, he is not obliged to identify a particular defect in the
    airbag system and nor was Ravani’s opinion rendered inadmis-
    sible because he did not identify such a defect. In this regard,
    the district court erred in excluding his opinion as to the
    existence of a defect. Again, the district court’s failure to
    appreciate the nature of the theory that Bensenberg was
    pursuing may well have been due to the lack of clarity in his
    briefing. But for the reasons we have set out above, we are
    satisfied that Bensenberg did enough to preserve the theory of
    non-specific manufacturing defect that he presses on appeal.
    This is not to say that expert testimony was not required to
    support Bensenberg’s theory of the case. The premise of
    Bensenberg’s claim of non-specific defect, after all, is that the
    vehicle struck the concrete post while traveling at a speed in
    excess of the front airbag’s deployment threshold. There is no
    direct evidence of the vehicle’s speed at the moment of impact.
    The vehicle’s EDR stopped recording the SUV’s speed when
    the vehicle became airborne after striking the earthen driveway
    crossing the ditch. And Ms. Bensenberg herself had lost
    consciousness. Consequently, the vehicle’s likely speed must
    be deduced from what information is available from the
    vehicle’s EDR, witnesses to the incident, and the damage to the
    vehicle, among other sources. This is not the sort of determina-
    No. 20-3407                                                          17
    tion that the ordinary layperson would have the capability to
    make for himself; it calls for expertise in accident reconstruc-
    tion. Toward that end, both parties offered expert opinion as to
    the likely speed of the SUV at the moment of impact.
    There is no real dispute that Ravani was qualified to render
    an opinion as to the vehicle’s likely speed at impact. Given the
    ground on which the district court excluded Ravani’s opinion,
    it was not necessary for the district court itself to reach the
    matter of Ravani’s qualifications.4 But the record makes plain
    that Ravani has extensive experience and expertise in accident
    reconstruction, such that he is qualified to render an opinion
    on this point. Chrysler itself raises no question about Ravani’s
    expertise in this regard. See R. 42 at 4; R. 55 at 1; R. 20 at 8 n.4.
    Its focus instead is whether Ravani’s opinion is admissible
    absent him being able to identify a specific defect in the airbag
    system, and we have resolved that point in Bensenberg’s favor.
    Nor, for purposes of this appeal, do we discern any obvious
    fault with Ravani’s methodology. Ravani appears to have
    taken the same general approach to estimating the vehicle’s
    speed at impact as the defendant’s expert, Matthew Weber:
    that is, he looked to the evidence bearing on the vehicle’s path
    of travel, the available data regarding the vehicle’s speed at the
    moment it became airborne, the distance the vehicle traveled
    when it returned to the ground, and the clues offered from the
    damage that the vehicle incurred as a result of the collision. R.
    55-2. The two experts obviously reached different conclusions:
    4
    Bensenberg contends that this was an error on the court’s part, but we
    disagree: the court could rightly assume his qualifications but find his
    opinion inadmissible on an unrelated ground.
    18                                                            No. 20-3407
    Weber opined that the vehicle was traveling below the airbag
    deployment threshold when it struck the post. R. 55-2 at 18.
    But Chrysler points to no flaw in Ravani’s methodology that
    would render his opinion inadmissible or that would preclude
    the facfinder from relying on it. See R. 20 at 9 (“Defendant has
    not argued that these methods were unlikely to produce a
    reliable estimate of the Aspen’s speed at final impact.”).5
    Indeed, as we have already mentioned, the district court itself
    had no quarrel with the admissibility of Ravani’s opinion that
    the vehicle was likely traveling above the airbag deployment
    threshold at the moment of impact, which was the very
    purpose for which plaintiff offered his opinion. R. 20 at 10.
    What remains, then, is whether Bensenberg has presented
    enough evidence to make out a prima facie case of strict
    liability for a manufacturing defect, within Illinois’ framework
    for a claim of non-specific defect. On the limited record and
    arguments presented to us on this point, we conclude that he
    has. Again, Bensenberg’s theory is that under the circum-
    stances of this accident, the vehicle collided with an immovable
    object, the concrete post, while traveling at a rate of speed
    above the airbag’s must-deploy threshold. Ravani’s opinion
    was offered to establish the vehicle’s likely speed on impact,
    and he concluded that the vehicle more likely than not was
    traveling closer to 53 miles per hour (the last recorded speed
    5
    Chrysler has argued that Ravani was wrong to rely on the state police
    officer’s observations as to the path and distance the vehicle traveled after
    leaving the roadway in making estimates as to the vehicle’s likely speed
    when it impacted the post. But, in context, we view this as an objection to
    the weight that the factfinder should give to Ravani’s opinion rather than
    a potentially disqualifying objection to his expertise and methodology.
    No. 20-3407                                                  19
    on the vehicle’s EDR) than to five to 10 miles per hour. If
    credited, that opinion tends to rule out the most obvious and
    likely secondary explanation for the airbag’s failure to deploy:
    that the vehicle’s speed when it struck the concrete post was
    below the airbag’s deployment threshold. And given the data
    from the vehicle’s ACU indicating that the airbag system was
    functioning properly at the time of the accident, a factfinder
    could infer the airbag had not been subject to abuse or tamper-
    ing that might interfere with its operation. This in turn would
    permit an inference that there was a non-specific defect in the
    vehicle’s airbag system that accounts for the front airbag’s
    failure to deploy.
    On this record, then, there is a fact question that precludes
    summary judgment in favor of Chrysler.
    III.
    The judgment is reversed, and the case is remanded for
    further proceedings consistent with this decision.