Bienville, you are correct. I am not a pilot. I simply read.
"From 2 h 10 min 05 , the autopilot then auto-thrust disengaged and the PF said "I have the controls". The airplane began to roll to the right and the PF made a left nose-up input. The stall warning sounded twice in a row. The recorded parameters show a sharp fall from about 275 kt to 60 kt in the speed displayed on the left primary flight display (PFD), then a few moments later in the speed displayed on the integrated standby instrument system (ISIS)."
I read that as the pitots froze up and the stall warning happened. I am not reading the "left nose-up" as being a violent movement such as would stall the plane. I am also reading this as the aircraft presuming 60kts is an obvious stall so let's warn the pilot he's about to stall. (There being no real unique stall warning.) That's the moment the fit hit the shan.
Now, what sequence do you see happening there? It is worded a little ambiguously. But it does seem to say the stall warning was coincident with the abrupt reduction in indicated air speed. And I take it as dead wrong. You cannot stop an aircraft that rapidly. (I read it as "seconds or less" not "tens of seconds" for the "sharp fall" from 275 to 60.
I certainly do not read a left-up control stick movement such as to the left around the storm (context, remember) as being the precipitating event to a real stall with no drop in air speed followed measurable time later by the "sharp fall".
If I am wrong, please clarify the quoted paragraph as you read it.