And I'm simply answering to what you want to know, I didn't say you're accusing me.
Joshtinusprime did grief, not once but twice. I chose to ban him because I wasn't going to wait for him to grief a third time, because it's completely unfair to other players to have their things destroyed or stolen.
By the way, I had a glass house that he completely destroyed. So I know for a fact he did grief. And I used the sponge to see again when he griefed Rainy's hotel.
If someone gets caught griefing twice, (and that's only being caught) they're probably going to do it as much as they please. I specifically asked him and the other two not to grief again.