Hi FG, its a classic case of watch the actions, forget the words. If I read you correctly he's still drinking at present? So he has nothing to fail at.
I myself didn't use AA or any other program, so I don't agree that it's absolutely essential, but given the other signs from your AA I'd say you're right. Before I gave up drinking for good I had so many attempts, and was just white-knuckling. I could give up for a while but always started again. I'm sure I could have used AA then, but I wasn't at that stage of admitting I needed it.
It's hard for your son though. Is he old enough to be sceptical of his father's words ? I suppose it will be a learning process for him over the next few years (assuming AH doesn't become sober), and it will be tough but necessary. Is he seeing a therapist or going to a group?