I know this is a smaller private server so we don't really have the opportunity to hire mods who have no vested interest in the game but perhaps a 30-60 day probationary period for new mods where they report violations to the established mods and are held back from banning (can still host events etc.) until they have proved themselves would help eliminate something like this?
I don't know the specifics here and also accept mistakes can happen so I am not taking sides just offering a suggestion