Robert Phillips (co-plaintiff) was wearing protective headgear manufactured by Century LLC (defendant) while sparring at a martial arts studio. When his sparring partner punched him in the face, the headgear’s face shield hit the bridge of his nose and cut it. The next day, complaining of neck and back pain, Phillips went to a chiropractor, who adjusted three vertebrae. Early the next morning, Phillips had a stroke due to dissection of his carotid artery, which resulted in severe brain damage requiring total care. Phillips and his wife (co-plaintiff) sued Century for negligence, defective design, and failure to warn about the headgear’s dangers. At trial, experts testified that a glove catching in an opening on the headgear could cause increased rotational force to the wearer’s head and neck. The defense experts countered that the chiropractic adjustment or some other event was more likely the cause of Phillips’s injury. A Century executive testified that the company had sold about 105,000 units of the model of headgear Phillips wore, but that it was “the only claim of injury ever made.” The executive said he had twice reviewed every insurance claim ever filed against the company, was involved in investigating all but two of them, and that “we went through every file in every department in the company looking for anything that might be relevant.” The jury found Century negligent in designing the headgear, but that its negligence was not a substantial factor in causing Phillips’s injury. The Phillipses appealed.