Is this considered child abuse?

My best friend's boyfriend is an alcoholic. She has 2 children and she told him early on that he can't drink around the kids. That was fine. He only drank when they were away for the weekend or whatever. About 4 weeks ago he got drunk on one of the weekends when her kids were gone, and my friend and him got in a fight about whatever. Eventually the fight turned physical and she called the cops. He has not been living with her, but they have been seeing each other. He has stopped drinking altogether, and says he won't drink again. He is also in AA and anger management, which he did start on his own in hopes of getting her back. Now she wants him to move back in. She says she will break up with him for good if he picks up another drink (she is a strong-minded girl, so I trust that she would). However, I worry about the kids. Is she putting them in jeopardy having him back in her house? Is it enough for me to contact child services?