You're unlikely to meet a bunch of friendly, stable and likeable people in IOP. Neither do we always come across such people at work, in AA, or even at home. I suffered through the unwanted company of people like the one you described while in 28-day rehab, and then in IOP. We're all called upon to deal with offensive and sometimes disgusting people in life. And we aren't always in a position to run from them, though it's not always best that we do so. Some of us even invite them to live with us, have children with us and become them when we're drinking.
Part of the therapeutic process, though I don't believe it's one that's always spoken, is seeing where we are and how we're progressing (or degrading) in comparison to others. If it were me (and it was while I was in IOP), I'd take it as an opportunity to turn the situation to my benefit, learn from it, and strengthen my self-concept relative to what I did not but might have become.