When someone is a good person (moral, honest, a man of his word), if he is in a situation to take revenge on someone who harmed him, when he does it, he will regret it later.
I'm like that too.
When someone wrongs me and harms me, it's already done and there's no going back. Is it worth wasting energy and time to "return the favor" to that person or just cross them off the list of people you are ready to give yourself to and cooperate with...
In my life, with some of my decisions and actions, I have certainly done evil to someone else for which he could have taken revenge (or took revenge), just as they did evil and injustice to me, for which I took revenge with the same or even greater injustice. And when I got my revenge (and sometimes overreacted) I wasn't satisfied. I felt sorry and I was angry with myself that I had acted like that and that I had caused damage...
I think it's very specific the situation and very difficult to generalise or comment from outside of the situation.