"How can 3 highly qualified pilots persist in maintaining a stall for so long without someone figuring out that they have got it wrong."
Probably because they were overwhelmed by the repetitive ecam messages,bells and lights.
I had something as simple as an IDG Low Oil Pressure warnings at rotation on the 320 and it was a major distraction. Every time I cnx the warning it came right back on until I leveled out and the oil covered the sensor. Lights, bells, trying to communicate with each other and ATC was problematic.
I can only imagine how difficult it was to decipher just what was going on in the heat of the battle. I am very reluctant to label this as pilot error at this point.
Springer