Here he is saying what we already know about overturning bans.

One pro of Merari is that he's an incredibly active moderator who spends all day every day modding reddit. And what boss doesn't love a worker who'll burn the candle at both ends for free? The downside of this, coupled with the fact that he'll take whatever mod actions he feels like on a whim, means other mods have to spend an inordinate amount of time looking over his shoulder to make sure he is doing what he's supposed to be doing. Don't worry though, plenty of subreddits don't care in the slightest about mod abuse, and I should know. If you find yourself banned from one, there is zero recourse to be unbanned. Admins will not overturn a ban, and few mods will overturn a ban as well.