EM drive is not an argument such that it might be refuted. It is a device. As such it has fitness for purpose, which depends entirely on the purpose at hand.
Snarkiness << skepticism.
Snarkiness << skepticism.
How about this alternative (which, btw, is how I interpreted the headline): "Principle behind EM Drive refuted" or "Experimental results of EM Drive refuted".
The quote wasn't meant to be snarky. It was meant as an explanation why it is worthwhile to occasionally do experiments, even if you believe the device can't work the way it is supposed to. He also said it was excellent experiment for the purpose of teaching his students.