the preliminary report implies that the design of the stall warning system may have been a major contributory factor in this accident.
The PF was confronted with conflicting signals as well as degraded instruments. Nevertheless, at quite an early stage, his inputs commanded nose-down pitch. He appears successfully to have initiated a recovery. What he needed to do, was to develop this response further.
However, the stall warning system did not recognise this. It did not encourage the PF to develop his solution further. On the contrary, it sounded a stall warning.
First mention of a nose down input is here:
2 h 10 min 16:
(...)The airplane’s pitch attitude increased progressively beyond 10 degrees and the plane started
to climb. The PF made nose-down control inputs and alternately left and right roll inputs. The
vertical speed, which had reached 7,000 ft/min, dropped to 700 ft/min and the roll varied
between 12 degrees right and 10 degrees left. The speed displayed on the left side increased
sharply to 215 kt (Mach 0.68) (...)
At 2 h 10 min 51, the stall warning was triggered again. The thrust levers were positioned
in the TO/GA detent and the PF maintained nose-up inputs.(...)
Around fifteen seconds later, the speed displayed on the ISIS increased sharply towards 185 kt;it was then consistent with the other recorded speed.
So IAS was well above 60 kt at this point. The stall warning simply meant they were going into a stall.
The only time a reappearing stall warning due to nose down / increasing IAS is mentioned is much later:
At 2 h 12 min 02, (...) Around fifteen seconds later, the PF made pitch-down inputs. In
the following moments, the angle of attack decreased, the speeds became valid again and the
stall warning sounded again.
But the report doesn't say anything at all about the PF's reaction to that warning.