Agree entirely with vilas.
Imho the use of the term 'deep stall' is a dishonest distraction in this case.
The term 'deep stall' was introduced, iirc, for aircraft whose configuration ( usually T tail) allowed them to enter configurations where the tail plane was rendered ineffective because it was washed by the wing turbulence.
In the AF 447 case, the airplane was stalled by the PF and then held in the stall configuration. As has been pointed out by others, just letting go of the controls might have save the day.
So no sign of a 'deep stall', except perhaps in the mind of the PF.
The legal case really should focus on AF CRM, the PM who was senior recognized that the PF was mishandling the aircraft, yet failed to intervene. That points to a serious weakness, but it still was not a 'deep stall'.