My guess, the guy who reported your AITA post was same mod who banned you...

Has happened to me before; On r\atheism someome made a post about how world is full of evil and suffering, thus god who allows that can't be good and it proves god can't exist. I commented how it's stupid logic, as if said god would exist, he could be the most evil thing in the universe, and still exist. Not to mention a god could definite that his evil is good, and humans couldn't say shit about that and how good and god doesn't mean same thing...

And one mod got severely butthurt about that comment, I don't know if he assumed I'm theistic or he just thought himself with said logic and didn't like that I pointed out he's idiot, and he got into argument with me, first just calling me names like a damn kid, and naturally seeing MOD comment your comment and only mocking how retarded I am by saying what I said, I told him he sounds like priest who got caught fondling his church folk and explains it as "If I'd touch kid, I would break rules of bible and thus I Couldn't be priest, and since i am priest, it means i couldn't have touched kids" and I got, maybe deserved, ban.

And next, to think it wouldn't pour when it rains...

Same day I posted on r\roastme and when I checked my post about hour later, I had permaban on that sub as well.

It was literally as perfectly rule following post as it could be, and when I demanded explanation, surprise surprise, very same r\atheism mod replied saying I'm too stupid to post on reddit.

I made complaint to big reddit but never heard anything off it and am still banned on both subs, not to mention handful of other subs that I don't even use, so I suspect he banned me on every sub he moderated.