The bottom line is, Ted was having an affair with Mary Jo, and he was drunk, and he did leave the scene of the accident, and failed to report it in a timely manner. Anyone else would have gone to jail for manslaughter
Ted was screwing whatever he could back then, but he had a German mistress as his regular squeeze. The girls on the island were all 20 something single girls partying with 30 + married guys. That was a formula for casual sex even back then. Ted made 17 credit card calls after midnight and before he reported it. Some to the mistress and a lot to his handlers and lawyers. He also arranged for his private pilot to ferry Mary Jo’s body to Scranton in one of them. Nixon had a guy there the next day investigating the incident and knew all this.