There is a theory that Mr. Kennedy wasn’t driving or even in the car. He panic’d when that cop car showed up while they were parked and he took off on foot, the publicity was something he did not need. Eventually Mary Jo tried to drive the big unfamiliar car at night on unfamiliar back roads and missed the turn off.
I watched a British documentary on YouTube that demonstrated that the island road had an intersection - turn left and you go to the ferry. Turn right, and you cross the unlit bridge where MJK and the car were found.
An off duty officer claims he saw the car after midnight at a dead spot and it appeared Ted was trying to have sex with MJK but the cop car spooked them. They coasted straight through the intersection and Ted probably got out fearing he would be caught.
Drunk and disoriented, MJK turned and drove down to the bridge while Ted, mussed but *completely dry*, walked past several houses back to where the party was and had aides drive him home.
When they got to the ferry, it had already closed for the night so Ted dove into the water and swam across the shore to return to his rental cottage on foot.
Teddy was chatting amiably the next morning over breakfast until an aide reached him and told him that his car was found with dead woman inside it. The aide said he turned white as a sheet.
A cover story had to be concocted. They decided it looked more innocent if Ted was driving and bravely tried to get MJK out before saving himself than to admit that he was committing adultery and wasn’t in the car.
They had some convincing interviews and diagrams.