8. The captain's erroneous speedbrakes "deployed" callout was likely made in anticipation (not in confirmation) of speedbrake deployment after he observed the speedbrake handle's initial movement; after the "deployed" callout was made, both pilots likely presumed that the reliable automatic speedbrakes were functioning normally and focused on the thrust reverser problem.
One of those things where habit takes over. Incidentally, I've seen this exact situation before. FO is PF, auto spoilers inop, and Captain calls out "deployed" after touchdown.
I've observed AA crews. Their SOP seems for the PM to keep his hand at the base of the thrust levers (just above the fuel control switches) during landing. I still can't figure why they do that. I wonder if it would be better for the CA to have his hand near the spoiler lever during landing while he is PM instead. That way, there's a tactile confirmation that the lever has moved. What do you guys think?