I think the better question is: how to stop a big aircraft...

I think the better question is: how to stop a big aircraft that's overriding pilot controls to execute nose dive!
As it engages auto-safety manoeuvre to save the plane from (perceived) pilot error, endangering the plane.

I'd imagine it would be quite hard for pilot to regain manual control when the safety mechanism has determined that the pilot is putting the passengers in danger?