Question: What happens when two players call the same tile for an exposure?

Answer: When two players call the same tile, the player next in turn gets the tile. However, if two players call the same tile and one player has started to expose their tiles, then they are entitled to the tile regardless if they are next in line to pick. The league states, “This rule is not meant to encourage aggressive play.  Slamming tiles or racing to put up an exposure is poor sportsmanship, not supported by the league.”

Source:  Mah Jongg Made Easy 2020 page 20 #13