H. Harry:
While no-one yet can presume they know what happened on MH370, it is clear from reading this document that investigators are working on the idea that the crew was unconscious for the larger part of the flight. Everything we know about MH370, and everything we've learned from previous accidents, would seem to point to the jet ending its flight after having spent a long time on autopilot."
It that premise is true, then it seems the crew would have been dead after a time rather than unconscious.