Question: What happens if a player exposes a single grouping such as NEWS?

Answer: If during the game, a player exposes tiles that do not complete a Pung, Kong or Quint, their hand should be declared dead by another player. The only exception to exposing a grouping such as a single grouping, e.g., NEWS or a Pair is for Mah Jongg.

Source: Mah Jongg Made Easy 2024, page 19(c)