In the back of my mind I seem to recall that an accident in the states ,was it Washington? lead to the change on the Boeing 737 from epr to n1.
I think from memory that one of the epr sensors had iced up and they thought they had set take off power when they were in fact considerably down on power, whereas if they had looked at the other instruments such as rpm,tgt, fuel flow or even throttle position they may have realised something was wrong.