banned me from server

I don't think this is an exceptional case. The moderators have hard facts and banned him because of engine assistance. The moderators are very good at this.

We couldn't even ban Sjeng users or guys using an engine every second move by your logic because "a 2300 rated player could do these move too".

I think he uses assistance but that game against Dragon was nothing special, he had a perfect and long pawn chain, its quite easy to play.