Questions: If during the game someone discards before picking and their hand is called dead, can another player call the discard?

Answer: Unfortunately not. In this situation, the discarded tile is considered “dead” along with the hand and cannot be called by another player.

The only exception is if someone discards before East has discarded their 14th tile, as the game has not officially started at that point. In this case, the tile can be taken back and the rightful East can discard.

Source: The National Mah Jongg League Bulletin 2022, Q & A #8