Page "Hercule Poirot" Paragraph 72

Hastings is a man who is capable of great bravery and courage, facing death unflinchingly when confronted by The Big Four and possessing unwavering loyalty towards Poirot.

However, when forced to choose between Poirot and his wife in that novel, he initially chooses to betray Poirot to the Big Four so that they would not torture and kill his wife.

Later, though, he tells Poirot to draw back and escape the trap.