“An expert’s rank speculation cannot masquerade as scientific knowledge in federal court.”
—Cory L. Andrews, WLF General Counsel & Vice President of Litigation

Click here for WLF’s brief.

(Washington, DC)—Washington Legal Foundation (WLF) today asked the U.S. Court of Appels for the Eleventh Circuit to overturn a federal trial court verdict built on unreliable scientific expert testimony  

The appeal arises from a lawsuit by Robert Lang claiming that a defect in Sig Sauer’s P320 pistol caused it to fire while holstered, injuring his thigh. Lang’s experts, James Tertin and Dr. William Vigilante, testified that the trigger’s faulty design allowed unintentional discharge. Yet neither Tertin nor Vigilante could say for sure what caused the gun to fire. Even so, both opined to the jury—without evidence—that a tabbed trigger would have prevented the accidental discharge.

In its amicus brief supporting reversal, WLF faults the district court for relying on outdated, pre-Rule 702 amendment precedent, which treats factual gaps in expert testimony as jury issues. But the 2023 amendments to the Federal Rules of Evidence explicitly rejected that approach, demanding judicial scrutiny of reliability. The district court’s stale precedent thus conflicts with Rule 702’s new rigor and is no longer good law. WLF also rebuts the trial judge’s view that any flaws in the plaintiff’s experts’ testimony go to the weight that testimony should be given, rather than to its reliability.