Can we say: "aircraft at altitude fly very fast. Why? They have to, or they won't fly"
Is that a different way of stating your opening above?
No, that was not the intent of the post.
If Bonin had used a strategy of control such as I described, the aircraft would have arrived in Paris. Since that is not what happened, it means he used an inappropriate control strategy. The question is why?
Did he have any experience hand flying at altitude? I am thinking he did not since he was flying extensively in RVSM airspace on autopilot. If he had any exposure to hand flying, it was almost certainly in Normal Law in a simulator.
Did he have experience flying in Alternate law with Roll Direct? As I understand, the answer is no. That training was reserved for Captains.
Did he have confidence in his abilities to hand fly? Judging from his performance, he did not. CRM went immediately out the window, and his PM was clearly distressed by his performance. This is the type of situation that could be expected to create strong fear in both individuals right at the start of the non-normal event. First Bonin, then Robert.