The Metro this morning (not that I like reading something linked to the Daily Mail btw, but if it's on the bus I'll read it) said that it was just speculation that he shot his own throat. But it did happen during a shootout apparently.
So knowing the US media's track record it's just as likely that they shot him in the throat and claimed he did it himself, as it is that he would've just done it himself anyway.
I guess it doesn't really matter, 'cos at the end of the day, he still had a bullet tear his throat to bits and he can't talk either way.