Question: What happens when a misnamed tile is called for Mah Jongg?

Answer: If two players call Mah Jongg, one on a misnamed tile and one on the correct tile, the player who has Mah Jongg on the correct tile gets the Mah Jongg. This is an example of how important it is for all players to look and listen when tiles are discarded.  This ruling is not found in Mah Jongg Made Easy. 

Source: National Mah Jongg League Bulletin Q&A (2020) https://www.nationalmahjonggleague.org