Regarding the initial stall warning:
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.
and
The airplane’s pitch attitude increased progressively beyond 10 degrees and the plane started
to climb. The PF made nose-down control inputs and alternately left and right roll inputs.
These two paragraphs make me wonder if the stall alarms were really spurious.
At that altitude the buffet margin at M0.82 for G - onset should be around 1,5 - 1,6g, maybe even lower given the fact that additional Roll input was commanded..
Also speed might already have been reduced to M0.8 at that point further reducing the margin.
Edit: Stall warning activates even before that, thanks @HN39 for the comment. /Edit
A firm Nose-Up input should be able to achieve this.
Please note: Protections were already lost at that point and the Stall warning appears to have been subsequent to the Nose-Up stick command.
Please also note the subsequent Roll inputs by the PF.
either they were in significant turbulence or it was a sign that the aircraft was already in the incipient stage of the stall. These big Irons with full wing tanks and immense roll inertia normally don't have much tendency to 'wobble'.