These problems could be solved by having the Hyperloop operate at 1 ATM - but then what advantage does it have? Could the action of pulling the air in front of the tube to the back create a lower pressure in front and higher at the back, thus helping to propel the craft?
I vaguely remember reading something like this. Would that make it viable?
That being said, I did not see him perform any kind of rigorous numerical or theoretical analysis of the problem, which would be the first thing an actual engineer would reach for. No finite element simulations, not even empirical napkin math: nothing. He didn't even analyze pi groups involved in the problem to prove similarity between his scale model and an actual functioning hyperloop. The end result is a for-your-entertainment-only youtube prop that has no bearing on the performance and reliability of the actual functioning model.