Unfortunately, I do know about alcoholism. My brother, who successfully completed rehab and is a recovering alcoholic, is currently living in my basement. Not to mention my father and grandfather, etc.
Maybe some alcoholics rant and rave about beliefs or feelings that they never before entertained, but that hasn't been my experience.
If Mel said those things, he's thought them before. IMO.
"You say outrageous things that you don't mean and often don't remember."
Maybe he didn't MEAN them, but I don't think they are alien thoughts to him. Again, IMO.
Given that his father is a looney holocaust denier, it's pretty obvious that Gibson was raised on anti-semitic ideas.
Doesn't mean he believes or means them when he's sober. I think he's got a lot of garbage in his brain's basement that percolates up when his alcoholism is raging.
I respect the fact that your opinion is every bit as valid as mine. We can't ever really know another persons heart. I'm not sure I even have my own figured out!