Well, to be fair, he could have been really drunk or high as a cope with his angst... Only the autopsy can reveal head injury/substance presence.

EDIT: Have you never attempted to type anything on a keyboard/phone when really drunk? Its fucking HARD.

So to immediately conclude that he suffered from head trauma (as opposed to deep emotional trauma) is short sighted, and like I said can only be revealed (hopefully) in an autopsy.