The rest of the story is a bit Rashomon-like in a "Men are From Mars, Women From Venus" kind of way. The other people in the restaurant were two people on a first date. The guy thought Gavin was noticeably drunk while the woman said Gavin was drunk-- drunk on love. The guy even told the Mayor's driver to get him out of there. The woman, however, would only say that she was jealous. The couple apparently will not have a second date.
As for the Mayor, Peter Ragone merely said "the mayor had a glass of wine and some pizza with his friend after being at a charity event at 'Beach Blanket Babylon." He then banged his head against the table for once again having to answer one of these questions.
Which raises another question: just how many benefits does "Beach Blanket" do? And imagine if you were the Mayor-- you'd have to see that play like ten or fifteen times a year. Not just for benefits, but every time some dignitary showed up because that's where they all get trotted out to see. By now, Gavin probably knows the thing by heart. In fact, we're guessing that's why he (allegedly) got drunk. He was probably sitting there thinking to himself "dear God, if I have to see that those Goddamn big hats one more time I'm going to lose it" and then killed the pain with some wine. And, actually, who could blame him?