[gordner]

I did not realise they had said it was on military radar, that usually means a primary painted target and not a lot of room for error.

They are equipped with quick-don masks that are very fast to put on, if you identify hypoxia is looming. Lots of crashes related to hypoxia happen from a slow decompression or a failure to pressurize in the first place, and the onset is so slow that it can be missed by the crew. Payne Stuart's incident is an example of that, but they lost communication shortly after reaching altitude and did not go down for a considerable length of time, so not so similar to this event.