So, uncontrolled pitch up due to overspeed protection is not an issue and the graphic at my post #85 here becomes the salient issue.
They did not have dual-engine failure concurrant to unreliable airspeed indication. SO, pitch / thrust (per the graphic) would have been the immediate watchword of the day. Given the facts, the memory items do not apply to the situation at hand (no imminent immediate threat to flight safety).
The aircraft stalled after climbing to FL380. That could only occur to due improper procedure per the checklist shown. Perhaps the PM read the wrong pitch to the PF?
Whatever the case, it was at FL380 that stall onset predicated the specific fundamentally - putatively ingrained - procedure to addres the very real imminent danger presented at that time; the procedures are mutually exclusive. Given the stall, pitch / power was untenable in that stall requires drop nose to checklist determined level, and increase airspeed. What airspeed given that IAS was unreliavble? Well, gee, when the deterrent buffet goes away it must be sufficient, eh?
Then attempt to return to level flight using pitch / power procedure as mandated by unreliable airspeed checklist. IF the stall returns, increase the pitch down maneuver by an additional increment to increase airspeed sufficient to depart from stall condition (repeat as necessary).
In theory this will ultimately rip the wings off. The only way that's plausible if severe icing has destroyed aerodynamics of the airfoil.
There's no evidence that severe icing sufficient for loss of lift occured though. I believe a reasonable explanation for pilot reaction: panic.
Muadib in Dune: "Fear is the mindkiller."
Don’t forget the aircraft was in the middle of a thunderstorm cell at the time, complicating the pilot’s ability to “feel” the aircraft.
Is it possible they thought the buffeting thunderstorm winds were the reason for the “wrong” readings on the VSI and AoA. Three minutes is an awful long time to maintain that false perception.