Lyman / HarryMann
I am not the right person to comment, having not been in a real high altitude aerodynamic stall since 1967 (not a passenger airliner, I hasten to add!), but stall recovery should never be considered an absolute given with a VSI of minus FLT100 per minute. The pilots had to both get the ND (the THS?) and not lose all control of the aircraft in the process. Never a certainty, even if the stall had been diagnosed in time. The critical period was shortly after A/P disconnect, to maintain stable flight and avoid the stall in the first place.