@ Jando - was the real aircraft airspeed < 60kts or was this an erroneous reading due to icing? It is a pity if it is the case that when airspeed is unreliable, or all 3 ADC disagree or are out of range, the stall warning computer decideds that the aircraft is not in a "real" airborne situation and decides not to play ball when the situation actually may be recoverable.
It would appear the absence and presence of the stall warning may have added to some of the confusion on the flight deck, though on some aircraft and dependent on pilot technique, the stall warning or stick shaker can be activated during recovery from the stall. But maybe these guys had never experienced this and of course its always easier from the armchair.
In system design, probability is regularly used when deciding how safe a system needs to be or how complex the logic should be. It may be that loss of all air data was of a suitably low probability to not be considered in the stall warning inhibit logic. As someone else said earlier maybe this is one of those 1 in 10000000 events.