How can you be sure that the co-pilot has the hours and the experience with the systems to be confident enough to take over from a "Non-Responsive Pilot"? In a rapid descent in any aircraft, heli, or glider in a spin, there is very little time....we were trained to be violent if necessary in taking over....
Confidence has to be part of the makeup of any pilot. I had to take over an approach being made by the Chairman of the Soaring Society of the USA, visiting our club, who was undershooting, and failed to recognise or respond when prompted! Doesn't matter who outranks you, you have to squeak up!
The first officer in the Canadian incident was hesitant. Training, as SAS says again and again, needs to cover recognition of the problems leading to a possible upset so as to keep the situation from ever developing.