never discount the subtle changes to the cockpit environment by having someone in the jumpseat.
on the other hand, the jumpseater may have been the first to call a warning.
I'm not sure what the guy was saying about DC8 throttles not moving...unless he meant that they had to be moved by hand. the dc9 had the same sort of speed control/command authothrottles for approach only...they ended up being disconnected to avoid mx issues.
Hand flying making the NFP work harder...too bad. You need to keep your hand current.
subtle incapacitation hasn't been mentioned has it?