Faulty Triggers or Faulty Testimony? Court Rejects Unreliable Experts in Design Defect Case

Colwell v. Sig Sauer, Inc., No. 21-cv-1200-BKS, 2024 WL 4216047, at *1 (N.D.N.Y. Sept. 17, 2024), is another recent instance of federal courts reinforcing their role as “gatekeepers” to ensure expert testimony is both relevant and reliable.

In Colwell, the plaintiff was injured when a Sig Sauer P320 handgun allegedly discharged unintentionally into his thigh. The P320 “functions as a single-action pistol,” and while it has internal safeties “designed to prevent inadvertent discharges,” it lacks external safeties, such as a manual thumb safety or tabbed trigger safety. Id. at *3. To support his claim that the absence of any external safeties rendered the gun unreasonably dangerous and defectively designed, the plaintiff relied on testimony from two experts: a gunsmith and a human factors engineer. Id. Both experts opined that “the combination of [the P320’s] extremely short single-action trigger-pull and lack of external safeties makes it far too easy for the trigger to be accidentally actuated,” and that these design defects were the proximate cause of plaintiff’s injury. See id. at *3, *5.

Sig Sauer moved to exclude the experts’ testimony as speculative and lacking a reliable foundation under Federal Rule of Evidence 702.^[1] Id. The court granted the motion, finding the causation opinions “do[] not pass muster under Fed. R. Evid. 702.” Id. at *4, *6. The court concluded that neither of the plaintiff’s experts had adequately tied their opinions to the specific facts of the case, nor had they conducted any meaningful testing or analysis to support their conclusions. Id. Instead, their opinions were “connected to existing data only by the ipse dixit of the expert.” See id. at *5.

For example, the court observed that plaintiff’s human factors expert had “severely limited” knowledge of this incident given that he had not personally inspected the firearm or holster. Id. at *4. The expert also could not explain a discrepancy between a police report and the plaintiff’s testimony about whether the gun was holstered when it discharged. Id. Additionally, he offered no opinion about what caused the trigger to move, admitting it was “possible” that something could have gotten into the trigger while holstering, causing the gun to discharge. Id. The court found that his testimony revealed a “significant analytical gap” due to his limited knowledge of the incident, consistent with previous cases where his reports on P320s have been criticized for being repetitive and lacking consideration of specific case facts. Id. Consequently, the court excluded the expert’s testimony as “not based on the specifics of Plaintiff’s incident” and supported only “by the ipse dixit of the expert.” Id. at *5.

The court similarly criticized plaintiff’s gunsmith expert for making broad assumptions about firearm safety without addressing the specifics of the plaintiff’s incident. Although this expert inspected the plaintiff’s P320, an exemplar P320, and several competitor pistols, and reviewed videos of similar incidents, he admitted during his deposition that he had not reviewed any file materials related to the incident. Id. He further conceded that his understanding of the circumstances was based solely on the plaintiff’s description. Id. He also did not inspect the plaintiff’s holster and was unaware of whether the plaintiff’s hand was on or off the pistol when it discharged. Id. Lastly, the expert speculated that a “foreign object or pressure against the holster” could cause an unintentional discharge, but failed to explain “how a tabbed trigger would have prevented the accident if a foreign object, such as an article of clothing, had been caught in the trigger.” Id. As a result—and consistent with other court rulings excluding similar testimony from the same expert in other cases—the court also excluded the expert’s causation opinion as speculative and lacking empirical support. Id. at *6.

With no remaining admissible testimony, the court granted summary judgment for Sig Sauer, finding that without the expert testimony, the plaintiff could not prove causation—an “essential element” of his product liability and negligence claims. The court noted that the “mechanics of a P320 firearm are not within the common knowledge of a lay person,” and furthermore, that the plaintiff had not ruled out other potential causes of the discharge, such as accidental contact with the trigger. Id. at *6-8.

Strategic Takeaways

The Colwell decision underscores the necessity for expert testimony to be firmly tied to the specific facts of the case, rather than relying on broad or unsupported assumptions. The ruling illustrates that courts will exclude expert opinions that fail to account for the particular circumstances of an incident, emphasizing the importance of thorough, case-specific analyses in proving causation in product liability cases.

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[1] Under Federal Rule of Evidence 702, the proponent of expert testimony must establish that (1) such testimony is based on sufficient facts or data; (2) is the product of reliable principles and methods; and (3) the expert reliably applied those principles and methods to the case’s facts.