It is not a good idea to insult someone who is willing to keep the server up.
Yes, when you donate, you do get a special advantage over the other players, but if you donated, why not get that special advantage?
One thing you must remember though, it is NOT a good idea to keep a conversation going if you know it will not turn out so great. A better idea is just to call for a moderator and walk away. If you can solve the problem in a manner which is appropriate, then you should, but remember that a moderator is there to help you.