I was thinking the same thing as the announcer, what if they wait until the last second when the defense has relaxed. At least two of the Niner players were turned around, looking the other way, when the clock ran out.
Good point from the announcer. What about waiting until the last second and actually snapping it. It would have a chance to catch the D off guard because at that point there's probably no way they are expecting it and are just focused on not jumping offsides.