AOA above stall doesn't matter much. No it wasn't 90 degrees but it was held above stall by the PF for over 3 minutes. That is what caused the crash and the PNF not intervening. 1 G is a constant like going down an elevator, descent rate doesn't matter once established. The only way they had to save themselves once in the descent was to lower the nose if possible so they could be unstalled to generate the G's to recover. No one did that.
Why? You learn that in the first 5 hrs of flt training.