Originally Posted by bealine
I don't know the full legal ins and outs, but in the USA the airline is legally bound to return to stand to let you off the aircraft until it's actually rolling along the runway!
There was thread on the AA forum a couple of months ago that would seem to dispute this. Someone got a phone call saying that his brother had been shot dead in Chicago. He was on the ground at ORD, and the flight had just been given clearance to taxi after a long delay.
The short story is that the captain wouldn't let him off, so he had to fly to New York. By the time he'd got there, there were no flights back, so had to spend a night in New York.
Cheers,
Rick