Deep stall is a relative term when applied to modern aircraft.
A Deep Stall is fatal for a human pilot in todays jet fighters, because they have basically in everyday language moved the C O G to a minus % to gain better turning in a close in fight.
If he goes too slow the plane goes into a "departure" from which HE can not escape as long as he fights the plane.
If he lets go of all controls, the computer saves his butt.
It is all relative.