He did come off as a unique individual. I think he's possibly uncomfortable in his own skin. He talks a lot in the affirmative "I'm a big guy - you couldn't take me", "I love to walk home. I'm a big guy, nobody will bother me", but it never felt natural.
I mentioned this the other day - it's a dangerous game to read too much of anything into these series (or any documentary). This is what I do for a living and things get left on the cutting floor that would change your perception quite strongly on things. And yet it's hard to shake the feeling with Casas as his whole demeanour seems similar every time he's interviewed, any time he speaks, and it matches up with the series somewhat. It's almost like he's constantly living an act, while trying very hard to act like it isn't. Of course, I could be way off.
I have never really like the kid. After watching the show, I found myself feeling sorry for him. He seems lonely.