Seeing that, the human body and mind is often put to challenge, at hard times. In such conditions, the yardstick for human behavior changes drastically, as our feelings often takes over and causes us to do things that we will regret. As readers we know that, we usually make mistakes at hard times, as we often say things we don't mean and do things we wish we had not. Amir's case was no different; he was put into a difficult position and had done something that he regretted.
This is shown after the incident, when Amir had turned an insomniac, as his dreams had brought back memories of Hassan. The significance of this is that, it shows that Amir still have some moral grounds and is displaying some form of remorse, unlike Assef. Even whilst being a successful novelist in America, Amir had found it in himself to repent for his sins, embarking on a journey to Afghanistan to save his nephew. In spite of Amir's actions, we can see that the events of that cold winter day in 1975 had brought forth both the best as well as the worst in Amir. On the other hand, whether he has atoned for his sins or not is up to our own