MG
My heart goes out to you. .as the others have said don't beat yourself up with "what ifs or what shoulds". Nothing you could or would have said would made a difference. he was in relapse before he picked up by slacking off meetings and being totally obsessed about the girlfriend.
You are lucky if he can be committed involuntarily to a psychiatric unit while intoxicated. That can't be done here in Pennsylvania.
When he comes to he will be sick with sorrow and remorse I bet. Then He can make the decision again if he wants recovery.
It is just hard work to stay in recovery . . real hard work initially and he came to a screeching stop and the inevitable happened. The nature of the beast of this damn disease. I hate it.
Take care friend. .Mo