To be fair, it sounds like this crash caused airlines and regulators to demand much more adverse event training, including high-altitude stall recovery. But according to the article, Airbus hasn't addressed the split control issue…
Q: How many pilots would attempt a stall recovery if the aircraft's instruments were not indicating they were stalled?
It's not that simple.
When the aircraft's computer considered the inputs invalid, the stall warning was muted. When they decreased the pitch (would be essential to recover from the stall!) the stall warning sounded.
"The angle of attack had then reached 40°, and the aircraft had descended to 35,000 feet (10,668 m) with the engines running at almost 100% N1 (the rotational speed of the front intake fan, which delivers most of a turbofan engine's thrust). The stall warnings stopped, as all airspeed indications were now considered invalid by the aircraft's computer because of the high angle of attack. The aircraft had its nose above the horizon, but was descending steeply.
Roughly 20 seconds later, at 02:12 UTC, Bonin decreased the aircraft's pitch slightly. Airspeed indications became valid, and the stall warning sounded again; it then sounded intermittently for the remaining duration of the flight, stopping only when the pilots increased the aircraft's nose-up pitch. From there until the end of the flight, the angle of attack never dropped below 35°."[0]
For me at least, it seems like the condition where both pilots are inputting control on the stick or rudder is always an error condition. Even if they're both inputting the same inputs.
The scheme directly contributed to the crash for two reasons; obviously if the co-pilot wasn't pulling back on the stick, they would have been able to get out of the stall. But additionally, the two crew members were spending crew resources on redundant tasks: both of them thought that they were the ones aviating and the other was in charge of figuring out why the flight computer seemed to be behaving badly. Possibly if one of them did dedicate their attention to the flight computer, they'd have figured out what the actual flight parameters were.
That seems like a crucial functional omission.