Yes - but for the purposes of the argument the velocity of the propagation does change. Semantics aside, he was correct.
Your man that you linked to, whilst full of info is not a particularly pleasant chap is he. I've rarely seen someone so impressed with themselves.
You are absolutely correct. He is arrogant, but in a comic way. He resembles the guy from S.P.E.C.T.R.E. the bald boss guy. And if you realize his arrogance is just for show and comedy, then you appreciate his ranting more. Annoying, but truthful.
Ken Wheeler for president.. I say.