Chris Scott, an A320 driver, is one of very few current pilots on this thread who knows what caused this prang... as most current professional pilots do!
I am sure Chris and the other professionals on this thread are flattered by the confidence shown but I doubt any of us would claim to 'know' what happened. We don't even 'know' that the aircraft was in extreme turbulence, or that it was involved in a 'super stall', as many seem to believe. Sure, we have a few hunches and most of us would guess that the combination of unreliable airspeed, surprise, an orchestra's worth of warnings, night, and presumably turbulence, could easily overwhelm the best.
For my part I suspect that when the facts of what happened are revealed (not long now) the discussion will then dwell on how well prepared the crew (any crew) were for such an event. Most pilots learn their trade on light aircraft with straight wings, direct controls and modest performance; the transition training to high performance swept wing jets spends most of the time on systems issues, and relatively little (none?) on the subtleties of the new environment in terms of basic handling. I have said in earlier posts, on the previous 447 thread and the A320 crosswind landing event, that the outward similarity of the basic C* control laws on the later Airbuses to earlier conventional controls disguises some even more subtle differences that demand changes in the way pilots react when left in sole charge of the beast. I don't believe adequate consideration is given to these matters in training. I hope people will consider that before condemning the unfortunate AF crew.