Martin and williams, two business partners, agreed that each would insure his life for the benefit of the other. on his application for insurance, martin stated that he had never had any heart trouble when in fact he had had a mild heart attack some years before. martin’s policy contained a two-year incontestable clause. three years later, after the partnership had been dissolved but while the policy was still in force, martin’s car was struck by a car being negligently driven by peters. although martin’s injuries were superficial, he suffered a fatal heart attack immediately after the accident—an attack, it was established, that was caused by the excitement. the insurer has refused to pay the policy proceeds to williams. does the insurer have a valid defense based on martin’s misrepresentation? explain.