Yeah, this looks quite contradictory doesn't it? Now, let's look at the context and see if it really is.
Some guy calls Chomsky a moron, I find that rather moronic (that is, calling Chomsky a moron, not calling someone a moron), so in general terms he exposed himself as a moron by calling someone else a moron, and I put that forth as a nicety. It simply does not follow that I find the act of calling someone a moron moronic per se.
If this supposed contradiction of mine makes you feel better or is somehow comforting, feel free to misunderstand me in any way you see fit.