It was definately rolled. I was a firefighter for 14 years, and I can't begin to count the number of MVA's I have been on where the bags did not deploy. Unless it is a high-end auto, it seems to need a direct front or rear impact to set them off. Then again, I remember watching a training video where a firefighter was doing extracation on the driver when the bag when off. Launched him out of the car!!
The were pulling the steering column up with a chain around the column, ran over the hood, and hooked to the frame behind the front bumper. Then using the spreaders (jaws) the chain gets pulled tight, pulling the steering wheel and the column up and away from the patient. Unfortunately, it compressed the bumper enough to set the bags off!