Pick-up comparison
The fact that a Hilux is not designed to be pressurised is beside the point. Leakage of window- and door-seals when the world outside goes low-pressure is something that you experience over a matter of whole seconds. If pressure were built up gradually inside the truck it would leak out. But this is not what we are dealing with. An O2 tank takes a few milliseconds to fail. The pressure-wave from this event completely demolished the vehicle, a robust structure.
This incident also demonstrates that spontaneous failures happen. (I acknowledge that we do not know the history of this particular bottle.)