The offensive line started down field eliminating any chance of a forward pass which would result in an illegal man down field, offensive penalty, 10 second runoff on the clock, game over.
Any defensive penalty would have been offset by the illegal man down field, play dead, no time left on the clock, game over.
There was six seconds left on the clock at the snap. A muffed snap and a sprint to the sidelines would have taken too long and falling on the ball and calling timeout would have defintely put the kick out of Bryant's range. But then again, they could have had Shockey kick the fieldgoal right Mr. Collinsworth?
I'd have to see a reference to a specific rule on that. Someone else here thinks that the game cannot end on offsetting penalties.