You could start a thread on Aikiweb and try to ruin his reputation. Assuming everyone can figure out who you mean. Seriously, we have dojo search, showing all of 3 studios in Eugene, OR. I'm going to guess this has already blown up in your face.
There is a flaw in your proposal that a thread should be started to ruin the reputation of the Sensei on Aikiweb., namely the risk of defamation of somebodys character.Would you risk the possibility of legal action being taken against you , if the name of the sensei was ever revealed?i would not and I think Jun would not be prepared to do as you suggest, at least without real proof.