[andyfox]

From the site you referenced:

Detective Bernie Flynn: "I figure, we've got a drunk driver, Ted Kennedy. He's with this girl, and he has it in his mind to go down to the beach and make love to her. He's probably driving too fast and he misses the curve and goes into Cemetery Road. He's backing up when he sees this guy in uniform coming toward him. That's panic for the average driver who's been drinking; but here's a United States Senator about to get tagged for driving under. He doesn't want to get caught with a girl in his car, on a deserted road late at night, with no license and driving drunk on top of it. In his mind, the most important thing is to get away from the situation. He doesn't wait around."

Exactly what I think happened.