Just my personal opinion, but if we really want to get to the core of the nose up control input, I think we have to look at PF's control problem.
Something along the lines of what he did versus what he should have done. If Grity's chart of control motions is accurate (and not overly interpolated/smoothed) then PF used an inappropriate control strategy.
Having never flown an Airbus, I'd like to hear from those that have, regarding control strategies used in Normal Law, and Direct Law.
For example, from the videos recently posted, it appears that the majority of Normal Law control inputs are pulses away from neutral, but sometimes in two axes simultaneously.
Is direct law also done with pulses, or is it a continuous input? (I have to assume that Alt2 Law experience with mixed control modes is very unusual/scarce.)
As I mentioned in an earlier posting, Grity's chart shows a lot of diagonal control inputs along the NE-SW axis. I really think PF was having difficulty separating his lateral inputs from his pitch inputs, probably due to an improper stick grasp.
I'm posting grity's image again below for convenient reference.
