Everyone who has worked in an Islamic organization has come across someone who made them angry. The question then arises - how do you deal with it? Do you forgive the person? Or do you teach them a lesson through discipline? The long answer is that it depends. It depends on what your course of action is, the intended consequences of that action, and how likely those intended consequences actually are.
The short answer is: On your deathbed, you may regret punishing or disciplining someone, but you will never regret being graceful - even if it was the 'wrong' decision.