"2. The aircraft did not climb immediately, it started climbing ten seconds after pilot input. (Also BEA). Could this have added some urgency to the NU input? Not unresponsive but "lackluster response."? Or could this be data input problem that caused a too extreme Pitch target? see below, g value?
"3. You mean that the PF climbed against the PNF's recommendation ?"
That's hard to say. I did not read (certainly did not hear) "Unable" from PF. I am concerned that the PNF is seemingly quick to abandon his alarm about the ascent; did he suss PF situation (as it was perhaps) the A/C would not Pitch down, at least not sufficiently to arrest or reverse the ascent?
"5. An aircraft not responding to control inputs would be classified as a catastrophic failure and should not occur more than once per billion flight hours. It was not the case this night."
Not my inference, only that the A/C was initially slow to respond to NU. This would be important as it may have set the stage for over control in Pitch, as we see with Roll?
Not discussed, but is it agreed that Automatic Trim might well be inhibited with the loss of A/P and UAS? It seems to me a straightforward and (existing) trim value should be sustained? The goal in manual flight is maneuverability? Not Trimmed cruise or a not necessary pitch bias? It turned out the trim ended up biased fully NU, eliminating any sense of a neutral point with the stick? It resulted (imo) in giving the PF a confusing input as to stick position, and authority? He was concerned with Overspeed, ("do you think we have some crazy speed?") not likely to push the stick forward to the stop and sustain it there?
That's pretty much what I have... The responses have been gracious, and illuminating.
Thank you to Winnerhofer, KayPam, and Uplinker