A small public correction can require more courage than a large private complaint.

Saying something in the room is a different act from saying it afterwards. A quiet word in the corridor costs almost nothing, while a mild sentence spoken while everyone is listening exposes you to disagreement, awkwardness and the memory of the person you contradicted. Size is a poor measure of nerve here, since the audience is what makes it hard.

Think of a moment recently when you waited until later to say the true thing. Consider whether one plain sentence at the time would have changed what happened next. Next occasion, try the short version out loud, said without heat, and accept the few seconds of discomfort that follow.