The reason for our not recovering was due to the extreme amount of trim the autopilot had applied while attempting to maintain the glide slope. The only way that we could have recovered would have been to apply extensive nose down trim during the initial recovery.
Very interesting. When practising stall recovery in the simulator we are usually in manual flight and only trim nose up a limited amount during the deliberate deceleration prior to recovery. I suspect very few B737 pilots have ever practised a stall recovery where the airplane was in-trim at stick shaker activation.