The torque converter (I think) will give you a lot more rolling distance than you think.Could be the driver didn't have the presence of mind to shift into neutral, so the car slowed down to a stop in a hurry. I've never had this happen to me, but wouldn't a dead engine, even with an automatic tranny, cause a vehicle to stop quickly? I'd think hydraulic lock in the heads would keep the crankshaft from turning over enough for the driver to coast to the shoulder.