I'm an alcoholic and have had a bit of this kind of reaction in the past....not normally after 30 days though. I remember one stint where, after a year or so, I would quietly look down on drunk people. It was egotistical and arrogant. I know better now. I guess I did this to fool myself...sick thinking in the end.
I now try to view everyone with compassion and non judgement. Not just alcoholics....everyone. Non addicts are as faulted as addicts. No one is perfect. We are all a mix of good and not so good. All of us.
This can also be reverse psychology. Its hard to admit the things we did when drinking. Harder yet to truly face and accept them. By judging others and being 'better than' he could be maintaining his denial. One cornerstone of recovery is learning that we only control our own behavior and reactions...this goes for everyone, not just addicts. Maybe by focusing his disgust on other drunks, he's avoiding his disgust with himself.