Both the Capt (pull up) & FO's (retract flap) reactions were consistent with only one scenario - tail plane stall.
Unfortunately, that wasn't it.
It has been a while since I have read about tail plane stalls (they're not relevent to my type anymore) but I seem to remember one of the ways of identifying one was that it's onset usually occured
a) with a change in configuration
b) at a higher speed than an aerodynamic stall
It almost seems that this crew had briefed the required actions for this scenario earlier and then carried them out because they had a mindset about it.
Pulling back on the yoke is not, IMO, a natural reaction to a low energy state. Raising flap is not either.
If the crew had talked about, (maybe in the crew room or anywhere else away from the CVR), the required actions in the event of a tail plane stall, it would explain a whole lot.
I wonder if this is going to be yet another accident where if the crew had counted to five before doing anything , they would have survived.