Airbus' have priority override button which will allow the pilot not flying (PNF) to take command of the aircraft. In hydraulic or "direct" flight controls, both sticks move at the same rate, you need to be stronger than the other pilot. Normally the autopilot and flight control system would have the authority to override the pilot actions (common on A320 etc.) but not all planes have that feature.

In addtion, if the autopilot or flight control system goes from a fully 'in the loop' mode to a 'direct mode' where input=output (the transition possibly being caused by faulty airpseed sensors in this case), the automatic flight control mode has no more authority to interrupt pilot command.

In situations like you describe where two 'free' (no force feedback in relation to control surface force) joystics are used, it is better to have a 'pilot in control' switch otherwise you could get situations where an inexperienced pilot would panic and force his joystick to an unsafe position, overriding the more experienced pilot.

See the following link for more info: http://msquair.wordpress.com/2011/09/16/pilots-in-the-loop-a...