Im proud of you for staying out of it... and dont worry about asking him to leave when he was not treating you well... I personally think that is wonderful, it does not matter WHY the behavior is unacceptable, the fact is it not and you will not put up with it.
BOY was I horrible when my ex-abf first started going to AA... Im not saying he was a saint but I was SO involved in his recovery, asking what they said, where the meeting was, going to his meetings with him, questioning the methods and letting him know loud and clear what I thought if I did not agree .... I look back now and feel ashamed of myself.
Keep doing with your doing, take care of you and your baby.... keep the focus off him.