At our local club we play round of each PLO/HE. The situation comes up first hand of one of the holdem rounds. Action pre flop and flop is irrelevant, on turn player 1 is all in. As player 2 is thinking, the dealer notices player 1 has picked up the cards to the guy next to him and has thinks it’s Omaha. What’s the proper way of dealing with this? If it matters, the game is overall friendly, all the players know each other, and we generally let players get away with small mistakes.