I put great faith in Hazelnuts' analysis. The problem is in accepting it without further questions. The a/c's actual vertical speed was 1000fpm?
At the moment of a/p disconnect, does PF sit on hands? He has a Roll to the right to contend with also. Does he resist the urge to "Have the controls"? Because that means touching, and handling. Why touch and risk the displacement of the stick, if the book says 'don't touch'? Or, "Do not maneuver"? Sophie's choice? An after the fact pronouncement on an anonymous forum doesn't qualify as SOP.
Further, let us entertain that the a/c has not "settled" on 1000fpm, but was in some trend, and the PF felt, and understood the g forces to his satisfactory conclusion? Right or wrong, he is now 'seat of the pants', and that might be a bad thing. We know he is inconclusive about accel cues and audio feedback in the flight deck. In his own voice....
Was his flight path the result of a risky blend of poor memory/training/experience in hand flying with some 'cheek' input? TTex has posited armrest misplacement, and is it possible to believe that PF never got the chance to fasten his restraints after a conversation or other? The only clue we have of his re: stick work is his "I have been pulling for a while".
In the 5-10 seconds of loss of autopilot and manual acquisition, the die is cast. Following this 'potential' conclusion, we have examples of literally dozens of holes/cheese. My contention is that from this early point, the cheese was mostly hole, little cheese.