Not commenting on the alleged incident, but more of a general query regarding the 737 stall protection system with which I am not familiar. Is it actually possible to stall in the 'conventional' sense (ie, not g-stall or shock stall) an a/c fitted with a modern stall protection system.
My understanding of such systems was that they would ensure a minimum airspeed for any given configuration, and limit the a/c in pitch so that if level flight could not be maintained at the required airspeed, a descent would be the result rather than a stall.
