blah, mind games!
He wants to show you that he can not drink. This is what I've learned, addicts feel "less than" to everyone else. And then they meet a partner who is critical and they feel worse.
They get away from their "source" of criticism and then have this false sense of self. Thinking they felt like cr*p because the person they were with made them feel that way....Blame shifting
What he's trying to do it show you he is "a ok"
No contact is hard, but it will help you heal faster, but I understand wanting to keep the lines open because you have so many questions and your ties were not cut yet.
Not that I want in ANY WAY for you to get back with an active addict, but if history repeats itself, he will be trying to get you back as soon as he realizes he's not A OK and you'll be the best thing since sliced bread.
Years after my ex, he said to me that he should have never let go because I was the best thing that ever happened to him. OF COURSE I WAS, but he was THE WORST thing to ever happen to me. I won, he lost :-)