The drunk calls I made during my worst drinking days are probably the things I regret the most... I managed to really damage some important relationships, with family and other important people.
I don't think they ever looked at me the same way since.
As for what that call you received might mean: I wouldn't really give it too much importance.
Drawing from my personal experience... I don't remember most of my drunk calls and the ones I remember were made when my mind was in a very distorted emotional state. Out of proportion to reality. It's not like I was telling people lies during those calls, but the things I said were often mean and came from me seeing myself as the victim of just about everything.
If you want to give the guy a break, I think the best thing to do is to ignore the call. Or at least ignore the things he said if they were unpleasant.