Poor Mel Gibson. It's unfortunate, but I guess in this day and age you can't make a movie that's widely derided as being anti-Semitic and then blurt drunken anti-Semitic slurs at a cop without people jumping to the conclusion that you're maybe a little bit anti-Semitic. People are just judgmental that way.
Personally, though, I think people are being way off base when they say that Gibson is nothing more than a Jew-hating neanderthal. For instance, he also hates homosexuals.
I do wonder what he was getting at, though, when he said to the arresting officer, "Astroturf? You know who's responsible for that, don't you?! The Jews!"