Having finally caught up to real time on this thread, I would like to bring up something that occurred to me on first reading of the (English translation) of the BEA Update of 27 May, but which does not seem to have been discussed on this thread. The Update states that
At 2 h 12 min 02, the PF said "I don’t have any more indications", and the PNF said "we have
no valid indications".
Assuming these statements by the pilots have been translated accurately, I believe they were seeing far more inconsistencies on their cockpit displays than just UAS. I would not expect a pilot who doubted just the validity of his airspeed or just the stall warnings to refer to the situation as "no valid indications." It seems to me that either most of the information on their PFDs was non-sensical, or by 2:12:02 their loss of situational awareness was so severe that they were no longer trusting any of the instruments even thought some may have been valid.
I wonder whether their inability to recognize the stall was the result of incorrect, absent, or non-trusted attitude information? Even though the IR portions of their ADIRUs were functioning properly, might the system-detected invalidity of air data and/or AoA information have affected the display of what should be purely-inertial information? (Later on the same page the BEA makes reference to "angle of attack, when it was valid ..." which suggests they have DFDR evidence of invalid AoA readings.)