Interesting question!
I agree with jeppsbore, I'd imagine that the initial impact would probably fracture the glazing anyway. Whether the subsequent gap would be big enough to escape through is a different matter.
Back in my motorsport days I used to bind (using tank tape) a razor blade to my harness so that I could cut through the webbing in the event of the buckle becoming jammed (never thinking I might not be able to squeeze out the aperture, by the way!).
I'd probably opt for a stout axe (secured to the floor) and swing it like a madman possesed if I had to.
PD