If he's in a bar with a new girlfriend then he's drinking.
Not that it's any of your business what he's doing now ... but assume that he is.
He sounds a lot like my ex AH actually. Didn't need AA, no not him. He was cured! he would never drink again! that did last a few years, but he couldn't keep it up, not by himself, and he didn't want AA helping him. He would go to meetings, because that was my condition on him, but he would come home drunk, and his sponsor would say he hadn't seen him at a meeting in months.
How can someone 'clean' abandon his own daughter? well aside from men doing it all the time, I wouldn't assume he's clean. I would bet otherwise, myself. Sad as it is, your daughter may be better off without him in her life.