BOAC:
It seems that a number 1 priority is that AB recognise that their aircraft can stall....
Fully agree!
And number 2 is that when airspeed information, something that the flight control system relies on heavily, becomes unreliable, that autotrim of the THS should drop out with the autopilot.
We won't know until we can see the plot of stick motion but it seems to me that the PF didn't know, or forgot, that when he pulled back on the stick, he was trimming into the stall. Do we know that the initial pitch excursion was the result of some action of the flight control system and/or the autopilot, or was it the result of PF action in response to erroneous indications?