[sokoloff]

My read is that the approach was not unstable (it met stabilized approach criteria at all significant checkpoints) at the moment when the PF (co-pilot) become spatially disoriented and began giving improper control inputs.

This disorientation of the PF was the triggering event, which caused him to call the go-around [prior to stabilized approach criteria being violated], the approach to be terminated, and required the PM (the captain) to make corrective [and conflicting] control inputs. These conflicting inputs were not accompanied by the normal exchange of controls communications.

You are correct that the missed approach procedure was initiated before the controls conflict between humans began (but after the co-pilot's disorientation made him suspect a flight controls problem). I was wrong on that point.