Actually he is proving quite a lot with documents and links to documents and references.
It's more like that people don't bother to check them, and then claim he has no proof.
About his outbursts of rage, or whatever you wanna call it:
That's partly faked. He's proud of being in 2 Richard Linklater movies, and sometimes, I guess he tries to actually talk himself into that state. It's kind of a performance, like Becks fake tears.
If you actually believe he's nuts because of that, he's a better actor as it seemed to me.