I disagree. Part of rehab is learning to live with people who don't always do what you want and experiencing conflict in a controlled environment. Learning to move through life while experiencing discomfort without quitting, without making excuses, without using, and sucking it up buttercup, is, IME, a part of the program. Your A is not a doctor, he's telling you things that may not be reflective of what's actually going on (this was a hard lesson for me to learn, because why would he lie to me?).
That said, since he made the decision to cut out early (and let's be real, he just needed a reason) I'm proud of you for not inviting him back home. When my AH pulled this the first time around, it never occurred to me that I could refuse to pick him up and let him right back in the home where we left off. My hat off to you.