If a player claims a discard for mah jongg and the player’s mah jongg was in error, the claimed discard remains with that player’s dead hand and cannot be reclaimed or called by another player.
If a player declares mah jongg but has not exposed any of their tiles, they may change their minds and continue playing without penalty.
Players should verify a winner’s mah jongg before throwing in their hands. If the mah jongg was not verified, and a player throws in their hand and breaks the wall, they are responsible for stopping the game.
In a rare occasion, when two players declare mah jongg in error and another player has tossed in their hand