People get angry because we naturally learn by rebellion. This is the reason why, when you tell someone not to do a thing, everything in them will push them to do that same thing (Eve and the Apple) (a kid and naked flame i.e candle light).
It takes a trained mind and a humble personality to always accept when you are wrong or even look away when others are wrong to maintain peace. Plus some mistakes are as a result of rooted believe. So, you would have to address the believe before the mistake.