In my tribe, we have this old idea. Every day, when you wake up, you're a different person than you were the previous day. So it's rather pointless to hold a grudge. Noone really believes it literally, but we follow the principal behind it. Try not to let it bother you because to let it bother you is to let them win.
If this person is really out to get you, a witch hunt is not going to find them and could get you into further trouble. The best thing to do is bide your time and see if anyone baits you on the forums. If someone starts baiting you, notify a moderator.
Consider for a moment the probationary period on the forums. Moderators don't clear abusive messages from people on probation and the way probation works makes your account worth that much more when you finally get cleared. Letting people get you riled up inevitably leads to you having to go through probation again. Don't let them do that.
Basically, on the internet, a pacifist policy is usually the best policy. This is coming from someone who has been known to get into physical fights in the real world and is anything but a pacifist. Experience has taught me that you have to choose your fights, don't let them be chosen for you. On the internet, fights are not possible to win unless you're the system administrator or moderator (both of which are incredible responsibilities and stressful beyond measure).
Nothing I say is intended to be rude. My autism means that I do not know what is rude and what isn't rude. I apologize if I seem rude. It is not my intention.