Ya, but he doesn't actually justify his position. And to the extent that he does, his calculations are inaccurate. The only legitimate criticism he makes is the one about depressurization (all the others are trivial and can be solved trivially in ways that have already been addressed in the whitepaper). And fotunately for the hyperloop, his calculations on that one issue are off by six orders of magnitude, per the videos that respond to his video.