If one were an alien scientist trying to understand the mind of the human species, this incident reveals a fabulous amount of information. This information is at different levels of subtlety. At the gross level, one may conclude, there is scant regard for following rules unless they are physically enforced. There is a spontaneous refusal to accept ones mistake and apologise, even when ones actions cause harm and hurt to others. There is a lot more such information to be obtained at the gross level.
But the shrewd alien scientist will quickly spot that there are subtle components of the mind that are at play here. These subtle components are the ones that drive the gross components. Thankfully, one need not be an alien scientist to understand all of this. There is a part of us that can understand our own behaviour impartially and hence act with all the capabilities of the shrewd alien scientist. This part of us can at all times clearly notice that our minds instinctive action is to go outwards. By this, I mean, we like to blame external circumstances for the inconveniences caused to us (or at a minimum, put the root cause outside) - the words of in laws, the judgement of ones boss, the actions of subordinates at office, loud neighbours. It is always the other person who is troublesome. The mind can normally never acknowledge that it has also participated in creating the situation it finds itself in. This indeed is the very nature of the surface mind (which is the only part of our mind that is accessible to most).
But, when notices this and commits to oneself that one will turn the gaze within also, besides looking outside, one will find that there are countless opportunities to train oneself. If one gazes inwards too, each time there is such a situation, within a short period of time, the mind will become quite peaceful amidst situations which normally one would perceive as a crisis. This gives one the ability to deal with such situations skilfully while remaining completely peaceful despite the consequences.
The outgoing mind specialises in making rules. Most of us would have seen movies where the hero is madly in love with a girl who later on cheats him. This in different movies, either makes the hero a psychopathic women killer or a drunkard loser or a person with zero self esteem. In each case, the heroes mind picked up an opposite and made it a rule when what it was going after became too painful.
There are other day to day examples of us making rules. For example, if one works to change something which stubbornly refuses to change (for example, a society that is unresponsive to the massive challenges ahead, or a depressed parent at home), there may be lot of failures even after many years of sincere effort. In such situations, one is tempted to conclude that the other can never change and that it is only oneself that can change. Such rules only expose the knots in one mind. The outgoing mind tried to change something and in the process got hurt as the desired change did not happen. Hence, it went to its opposite (which may vary from individual to individual) and says only oneself can change and the other can never change. But, instead if the outgoing mind is reigned in, then it is possible to see that one can be perfectly prepared to face reality without making rules. So yes, if a depressed person at home refuses to change, it can be hard and hence we can only work on ourselves from getting frustrated and angry. But, there is no need to make a rule that we can only work on ourselves. If one is free of the dualities that ones mind has created in the past, then, if the depressed person do lend themselves to change at some point, then we may work with them too.
Thus, by training the outward going mind to also gaze inwards, one can learn to be perfectly poised to face reality and therein flow the situation and make changes for the better as and when the opportunity presents itself.