Your little angel now shows guilt and remorse if he knowingly or unknowingly does something wrong. He is closer to turning 8 and fairness and justice are things that he is learning from his exposure to outside world and also through the stories that he reads or listens to. His growing sense of empathy is also making him feel the pain of hurting others through his unfairness and wrong actions.
What you need to know
From the age of 7 years onwards, most children start building their moral ability. Your kiddo is now developing a strong sense of right from wrong and will be very serious about it. Lying and cheating are very important issues for him and he will get deeply hurt if his friend cheats in a game. He will be very vocal about it and will emphasize the concept of fairness repeatedly. Of course he is learning from your example and how fair and just you are is going to lay the groundwork for his concepts.