Of course he's lying. It would be nice if they would investigate this and find a cocktail waitress or bartender that would admit to serving the guy liquor before he took off in his car.
But knowing the Kennedy's these people are probably already in Vegas spending the "windfall".
You don't need to investigate anything.
He is a liar by his own addmission - his statement claimed that he asked for "no preferrential treatment" yet, at the time of the incident, he staggered out of his car and stated that he was "a Congressman and he was late for a vote" (WHICH WAS AN OUTRIGHT LIE).
So what do you think the intent of that statement was? Could it be to exert influence? Surely not...