This is what really irritates me about moderating in general. The whole thing is an exercise in power tripping. Considering whether a decision was misguided is forbidden. You must always be dictator. Mistakes are never made.
Devil's advocate: sports referees never admit a mistake, either. There's a calculus where the upsides of correcting a mistake are outweighed by the downsides of inviting more gamesmanship of your decisions.
(I know nothing about the SO situation, purely talking generalities here.)
I'm not sure about that, of course In a game they don't once the cards fall; but there's video review and officials do admit to mistakes after the fact. It's not quite so bad as the situation with moderators IMO. I don't see the same level of power tripping, but maybe that's because I'm not on the field
There is plenty of questioning moderator decisions on the stackoverflow meta, in civil ways where both sides can explain their actions and perspectives. Mistakes are sometimes made and subsequently corrected given the background and opportunity to recognize them.