I know you are but what am I?

My neighbor, the one that testified against my son for entering his house without permission, apparently wants to be friends with me.  However, I am not interested in a friendship with someone that had a chance to help my son and chose a course that resulted in J spending 5 months in jail and branded him as a convicted felon for life.  I was at a mutual neighbors house on Saturday and he showed up.  "Hi D" he said as he walked up the driveway. I responded in a hushed tone "hi" and proceeded to walk towards my vehicle to leave as I did not want any involvement with this former friend.  He came around the back of my car saying "D, the problems I have with J don't have to come between our friendship".  I replied "You violated our friendship" as I opened the door to my car and sat down  in the seat.  "So that's how it's going to be he?" asked with a hint of disbelief on his face.  "Yes" I replied.  "Your an asshole" he said just before I shut the door.  There are so many things I wanted to say to that man but I certainly was not going to create a spectacle in my neighbors driveway.  So I said nothing and continued to drive away.  He doesn't want my friendship.  He wants my forgiveness which he shall never have.