Earlier quoted context omitted.
Somewhere a redditor did the math and I believe it would have taken 24ms for the glass to break and the water to rush in. Instant death if it was indeed the glass.
Just how instant is that death? Do you die from quickly drowning in the water or is the water pressure enough to also crush your skull quick enough to make sure you die without having the chance to feel anything? Guillotined people can still be alive and feel about 30 second safter their head has been removed from their body.
Imagine a Ford F150 sitting on every square inch of your body.