As usual the “armchair, after the event pilots” are fast to give us obvious advise, like “fly the airplane,” but it seems to me that there is more to this than stated in the report, and IFixPlanes has highlighted the possible clue.
I am not familiar with the 734, but note from the report that the AP disconnect chime (which lasted for approx 4 seconds, according to the report) was cancelled by one of the pilots. I understand that AP disconnect should indeed have happened once ATT was selected, as it had been, so for TWO reasons the crew should have been aware of AP disconnect – the chime, and systems knowledge.
Now, bearing in mind that the likely flight conditions (according to the report) were marginal VMC, it seems to me to be highly likely that at least one of the crew would have been “flying the airplane” or at the very least monitoring the flight profile, and this is supported by corrections to roll that the report acknowledges did take place at this stage. Furthermore, in my opinion it is very unlikely that at least one crew member would not have responded to the subsequent bank angle warning, so I am therefore drawn to the conclusion that in the early stages of the upset, the crew were indeed monitoring the attitude indications, and controlling the airplane in response to them.
Could it not therefore be the case that in view of IFixPlanes post, the attitude indications they were responding to were actually erroneous? As one unfamiliar with the type in question I am unable to comment further, but 46 seconds is not far off 30 seconds - even for an armchair pilot accident investigator.