I was on the server at the time. To me it seemed like they were just bantering and the other guy didnt say anything about it so It did not seem to bother him.
I didn't mute him then and I won't be muting him for this now. I woldn't consider this heavy insulting but if a special admin sees this differently he could maybe be muted.
Thank you for your report anyway and I'm sorry if it is not a satisfactory result