If one of the pilots had noticed the hands of "" ... My old Sensitive Altimeter ..." spinning round ( say.. by FL33.0 ?), one of them might have noticed that the THS had reached an unusual reading of fully NU.
I am lead to believe that the THS FOLLOWS commands, from A/P or S/S.
( I had mistakenly believed that it might have been otherwise, until I was corrected by Tanaka.)
The A/P was off. The THS must have moved in response to a S/S.
Some airlines seemed to train that " the THS is something WE do not touch"
I do not know whether this was so in AF.
Never having operated under the PF/PNF system, I would like to be told the etiquette then used when pressing the " I have control button" when one is reluctant to yield to the other.