PKing low lvls

I just started the game in the last week and tonight have a friend helping me lvl because I was having a little trouble been about 3-4 years since the last time I played and some person decides he's going to make up claims that my friend was afk farming when I was literally sitting right next to him in my house on my own computer playing.
I'm sorry but stopping low lvls from lvling by killing the one that's helping them and then killing the low lvl for proving a point is rather pathetic and ruins the game for everyone. I have photos of the character if you want the name.