In Massachusetts claims are typically brought alleging negligence, breach of implied warranty (strict liability) and violation of the consumer protection act. Although comparative negligence is a defense to a negligence claim, an accident must be caused by a user's willful and knowing misuse of the product to constitute a defense to a warranty claim. I have experience defending these claims and have obtained some good trial results. A few examples are:
In Roberge v. Roberge, a jury concluded a bicycle was not defective resulting in a defense verdict for a homeowner who supplied a bicycle to his 13 year old nephew. The boy claimed the brakes on the bicycle were defective and caused him to crash into a mailbox, sustaining a broken jaw. At trial the world's foremost expert on Columbia bicycles testified that he tested this bike and it met CPSC braking standards.
In Burgos v. Danly Machine, a federal court jury found a warning on a 50 ton press was insufficient, but that breach of warranty did not cause the plaintiff's injury, resulting in a defense verdict.
In Sweetbrook v. INA, a jury concluded the insurer sustained its burden of proving a policy exclusion of "inherent defect" as being the cause of a rupture in a large commercial water storage tank. Here are some cases from my practice: