See, part of the thing with sobriety is you have to be willing to face people you have done wrong by and admit it and apologize.
I'm not saying what he did was so wrong, I exaggerated a pinch for effect. I just think if she spent a lot of time on helping him then he should at least give her the courtesy of dumping her to her face.
What I hear in between the lines is you're saying: "The woman was fool enough to be with a drunk, she doesn't deserve much respect because she doesn't respect herself." Well, Arabian also chose to be a drunk and maybe she really thought he needed her (some chicks have a serious problem with trying to rescue the world). Now he's choosing not to be a drunk, but in this situation I personally think the least he can do is break it off, ASAP, and apologize to the woman, and he should do it to her face.
Let's face it, he would never have created this thread if he wasn't trying to find some way to weasel out of doing the right thing, anyway

We ALWAYS know, in our hearts, what the right thing is, we just like to tell ourselves there's an easier answer somewhere. But the truth of life is that the right thing is almost always the hardest thing, the unpleasant fact, the bandaid over the hairiest part of your body that has to come off.