"The aircraft did not immediately respond..." BEA
This plays Hell with your primer, Lonewolf. Notwithstanding the Pitch was four plus degrees low on the pilot's AI. The STALL WRN suggests an AoA of extreme value, v/v cruise, and the a/c was maneuvering out of phase with its attitude, eg, Nose Low, and ascending.
At the very least, we suspect the airframe was not consistent with a ho hum cruise, and the a/p (imo) quit due controls/response out of limits. To include airspeeds discrepant: either disagree or simultaneous migration past a/p limit value. (30 knots < second and continuous). See the Mach variations as described above.
The only aspect consistent with a STALL Warning, at that speed, is AoA/Mach disagree, which is consistent with the accepted wisdom, here, as I see it, but not enough acceptance/credence is lent to the conditions extant at a/p loss/handoff/HAL malfunction.
It is troubling that without the conditions leading up to handoff, so many here have arrived at conclusions. You suggest a lack of skill is responsible.
The DFDR is reporting Inertial data, not what PF or even you would be seeing at the beginning (or 'continuation' of UPSET).
It is vital that the conclusion be exculpatory of the Bus. If due Weather, then the a/p v/v limits in stink is suspect. If a/p exceeded, the Bus is painted as poorly designed. How handy for a baby pilot to put them into the wet.
My starting point is that the crew inherited an upset airframe. The autopilot's limits are well past what is technically accepted as "Upset" in the regs. So naturally, ICE and inexperience are the uniform of the day.
The story is here, in the start, not at the (actual) STALL.