>>My husband had a large stroke, and he breathed normally for the first few hours. He was panic stricken, but you couldn’t tell from his breathing.
The inside lock mechanism works for 5 minutes and then turns off. It needs to be turned on again via a button on the flight console. Had the co-pilot been disabled, the 18 minute descent would have been over in 5 minutes. He must have re-toggled the door lock at least 3 times.
OK, this is a stretch - Imagine the co-pilot frozen in a position with his hand weighted against the toggle, unable to lift his arm, perhaps only being able to use some upper body motion (limited by seat belt) - or - completely incapacited because he was stroking out.
Perhaps the airlines will consider modifying the safety devise to accept a sequence of codes to over-ride that toggle for this kind of emergency, where two or more crew members have separate codes that must be entered in a rank sequence to break the security lock triggered by the cockpit's toggle.