The evidentiary battle over whether a defendant may offer evidence that a product’s design is in accord with customs in the industry or complied with government standards has ended. On Dec. 22, 2023, the Pennsylvania Supreme Court in Sullivan v. Werner issued its opinion, stating:

“The court (after considering a dozen or more appellate and amici briefs), in a definitive opinion, found that compliance with these standards simply reflects a manufacturer’s conduct and not any relevant information a jury must account for in deciding defect. Upholding other decisions issued in prior Supreme Court and Superior Court decisions, the court found that its 2014 decision in Tincher v. Omega Flex, 104 A.3d 328 (Pa.) did not alter the underlying precepts of strict liability in tort. Neither a product’s design adoption of an industry practice nor compliance with any government standard is germane to the risk-utility test a jury must apply in deciding defect. Evidence that a third-party, whether it’s an industry or government organization, has promulgated product design or performance standards, which the defendant or a third-party concludes is sufficient to allow the marketing of the product does not have any tendency to make any of the risk-utility factors more probable than not.”

In deciding not to follow the evidentiary rules adopted in some cases issued in other jurisdictions—which the defendant and its amici argued was the correct course of action—the court wrote that Pennsylvania’s precedent and its devotion to the principles of strict liability adopted under Section 402A of the Restatement of Torts 2d, requires that liability be gauged by juries even if a defendant exercised “all possible care.” Strict liability remains distinct from negligence in that it imposes liability without fault.