A 'stall warning' is NOT a stall... it is designed to go off a margin above the stall, the clue is in the name - else it would be called a 'stall INDICATOR'.
In the absence of any accurate IAS / alpha data, I would like to know exactly how all the armchair TREs here have determined that the aircraft was 'stalled all the way down', besides making wild assumptions from several grainy videos.
I see no evidence the ac was stalled all the way down - in fact, quite the opposite. The (ground?)speeds provided through ADS-B captured by FR24, the descent rate, the fact they had enough directional control to 'aviate' to an area of their choosing, the fact that the stall warner was intermittent, NOT continuous.... plenty of evidence to suggest they may not have been stalled. That they were close to the stall appears to be in no doubt.
Stop jumping to conclusions.