Is it possible that the F/O who was PNF in the left seat was also reluctant to take control because of a lack of dexterity with the LHS sidestick? As a F/O, primarily sitting in the right seat, his experience and dexterity would with using his right hand. Indeed, I have heard mentioned elsewhere that when two F/Os are on the flight deck, the PF is always supposed to be the one in the right seat.