stick was never held in the ND position for "10 seconds", there is a time period when it oscillates between NU & ND but is mainly ND for about 10" at around 17000ft
The period of time in discussion is between 2:12:33 to 2:12:43, around FL210. The ND position was dominant, the average value clearly on positive side of the graph. However, the elevator did not followed the input, it never passed half way from maximum of NU. Therefore,
"though very slow to respond"
is not due to the "developed" stall condition. But because the Dnz feedback response tends to fall off, due to lift loss and the airframe has a natural tendency to pitch ND. Then elevator is more and more driven NU, due to integration of the increasingly large CL error. Yes, there the pilot was right, but the aircraft response went badly wrong.
The automatic stabilizer trim function will only start moving ND after the elevator (not the sidestick) has moved from a NU to a ND position. I think even 30 seconds are not enough to straighten the THS from "braking chute" position.
I think there's a degree of doubt regarding translation
I think translation is accurate since it's copy/paste from Appednix 1 of the final report and the french verb monter = climb, nothing else.
I agree, Dubois warned Bonin to go down.
Bonin had to get on the stick, but only in roll, and not with such a heavy hand
He had a heavy hand or maybe the sidestick is not suitable for the hand of pilot in distress
I look to the roll command input vs the phenomenal NU input, between 11:40 to 12:15, I'm wondering what if he kept the sidestick inadvertently at max NU while fought to bring the wings to horizontal...