The problem I see is energy density. Sure there is pressure, but who wants to drive a bomb around. No matter how safe they say it is, 10000 psi is 10000 psi, and released too quickly your molecules are going to be scattered to the wind. Crashes are chaotic. I’ve seen kinetic energy do some crazy stuff.
Discussion
They have performed tests firing a 50 cal bullet into the fuel cells. They're practically built like an aeroplanes black box. You'll be disintegrated by the crash before they get damaged.
I’ll see if I can find some tests. Interesting. It’s still relatively low energy density compared to diesel though. Electric makes great sense for metropolitan transport, for freight and distances though renewable diesel is the ticket IMO.