In my view I have to side with Sylf on this one simply because the meaning of an insult is determined by the person that receives it. Not bystanders.
If Sylf had said "Hey nigga" to someone and that person interpreted as an attack, she would be in the wrong. I then would be up to the person she insulted to take it up with the Powers-That-Be (aka GMs). In short it is the receiver of the alleged insult to treat it as one or simple friendly banter.
I can go to a friend of mind and call him a bell-end. If he gets upset and takes it up with a GM saying I called him a dickhead, then it was on me for using poor judgement. But that doesn't happen. Why? I am a good enough judge of character to know if I engage in friendly banter with a friend, he will take it as such and return the same friendly banter back at me.
In that nobody has any say in the matter since it is between me and the person I am talking to. Nobody else.
Bottom line: If you are not involved in the conversation, then keep your brown nose out of it since it is not of your damned business.