To my knowledge, he was using the OSR (old school rifle), which when scoped in can travel through a brick layer (or 2 players potentially). Unless Psp modded it out, the OSR should be a part of the sellable items. The thing is, he would get the rifle before leaving his house: if he's a shop keeper, he must have a bank brick in his build, which is against server rules. If not that, then he's using abusive events, which is 20x worse and bannable.
So we'll see how it plays out around 4:30 tomorrow. (eastern, GMT -5)