I have seen people lock right up. And the other one just sits there. Totally possible. It is just how we are, we are fallible.
Was right seat in a Viscount simulator (white on black AH) when the left seat got it upside down at 16,000 and just sat there with me screaming in his ear we were upside down until we hit the ground.
Would be a good simulator scenario to have in the curriculum, but don't prebrief the guy expected to take over.