So, are you suggesting that a copilot who is "slow" with his instrument scan and had failed to monitor his airspeed and flown into the stick shaker should also "be expected to react correctly" to effect a timely recovery from an approaching stall . . . ?
Who is more culpable, the handling pilot who places the aircraft in an imminent stall or the PIC who allows the situation to deteriorate that far? I would suggest that whoever has their hands on the controls is in the best position to effect a recovery, unless it is obvious that the handling pilot is not in fact effecting a recovery.