I think we are digging into obscure academic areas and chasing our own tails again. It's been talked to death. Variable sensitivity controls are discussed in several previous posts, not least 3 posts before yours.
It's not unusual for pilots to 'cheat' by tweaking a bit of rudder, usually on approach at low speed. Different types have very different responses at this stage. They had a severe wake encounter, full control reversal inputs were applied either automatically or manually. The fin separated. At low flap retraction speed, it is more acceptable to apply full rudder than at cruise speed. It was the reversal that did the damage. Rather than discuss to death the principles of pilot input, I think we should satisfy ourselves that this is not some system error. If it is pilot error, we should all learn by it.