In actions to recover damages for negligently causing the death of a person or for injury to a person who is deceased at the time of trial of such action, the person for whose death or injury the action is brought shall be presumed to have been in the exercise of due care at the time of all acts in any way related to his death or injury, and if negligence of the deceased is to be relied on as a defense, it shall be pleaded and proved by the defendant.   [PL 1967, c. 494, §15-A (NEW).]