Well lets do some real world estimations. Your stall recovery in a sim in a A320 lost 18000 , and you knew beforehand you were going to stall and were mentally prepared for it (probably silently went over the actions in your head before the event), confident your life and limb weren't at risk, and still lost 18000!!!
Now a dark and stormy night, UAS, unexpected autopilot kick out, startle factor, fear for your life, as your past flashes before your eyes, would have to add a50% factor to it, makes a recovery possible in say roughly 27000 feet!
This should be added to every heavy jet training syllabus immediately!
Our company made a mod to the sim cyclic after thus event, on climb out "one " IAS failed and you had to determine which was the faulty one. Then we did approach to stalls at 37000 with a full panel. I don't want to be highly critical of my own company but for heavens sake talk about underdone!!
I have voiced my opinion to anyone who will listen and just get some vague platitudes, and then the listener's eyes seem to glaze over. It seems all too hard!
There have a number of high altitude loss of control events over the years, and AF447 seems to be just another one.