Sometimes it is not about personal gain but making sure that any unfair gains are worthless.
The best move is to avoid playing the game.
I think the person in question would be in vastly larger amounts of trouble for even raising his head above the cesspool he floated in for a moment. It would be like a chase from the Benny Hill show with local housing enforcement, HMRC, the police and a trail of angry and abused tenants.
The best move is making the game worthless so there are no winners. Shit on the board. It's a stalemate then.