I think it's a lot deeper than that. It's about the weight of the role of leadership. The officer's higher up talks to him about the incident and berates the officer for letting the cadet land the punch. The officer is just as upset about the situation as the cadet, if not moreso. To bear the mantle of leadership is to necessarily be better than those who serve under you. You have to always been at peak performance for the sake of those below you, even when engaging in duties that will already garner animosity. Going easy on the cadet when disciplining him, slipping up for even a moment now means that cadet has to be punished. It's as much a failing of the officer as it is for the cadet.

Leadership is a burden that must not be taken lightly, for failure has consequences for those in your care.