Had this happen a while back. Yanking on it with a vice didnt do anything as I couldnt get enough force on it.
The way I managed to break it free was to put a thick plank on the drive, then drive the car onto the plank trapping the bit inbetween the tyre and the wood. I then sat on the drive, drill between my legs and used my legs to apply the force whilst a mate pulled the chuck release back.
Worked a treat after a few yanks and the drill bit came out. What wasnt so awesome was that the bit popped out mid yank and I ended up smashing the heel of the drill into my sack.
A little lie down was needed after that one!
thats what i call a novel approach
didnt you have a vice?