Hi gums....
You say.... "Bottomline is that the 'bus gains actually provide a kinder, gentler handling when in the back-up mode. Not skittish or overly sensitive."
I think it is possible our PF noticed the above in Pitch, and when he determined his inputs could not effect rate, as in Roll direct, he traded rate for "holding" aft stick, (persistence). It would be the first time he experienced different "Law" in two axes. In selecting Roll as his preferred (Direct), he may have decided his efforts would have more effect in Pitch if held. A mistake, surely, but he had no experience flying by seeking g, another first time only time. Til then, the aircraft had always done it.
Bear in mind, most everything that happened after a/p loss was a first time event in the aircraft, along with a deluge of alerts. He appeared terrified of G<1.
His training had been nothing like yours, not his fault. I don't think it is equitable to slam him for trying what he thought would work. Not that you are, I think you get what he was up against. The sobering thought is that he was one of thousands who might have the same responses to unexpected gremlins.
Respect,