Time of USEFUL Consciousness?
Ask ex-military aircrew who's done the advanced farting class at RAF North Luffenham or elsewhere, albeit under controlled conditions, and you might appreciate the priority is to get down to where the human brain can make sensible decisions with adequate O2.
Or maybe read the Helios accident report and ponder the ability of the advanced Bonobo chimp to survive in such a hostile (lack of) atmosphere?
Now that 737NGs and other craft are pottering around routinely at 41,000', please appreciate there's not a lot of time to fanny around whilst the cabin altitude rockets up to silly levels.
The adrenalin perceived in the F/Os voice is perfectly normal in such circumstances, even when being practised in the simulator, without the REAL fear associated with such an event.
Your relative is around to talk about it, for which we should rejoice?