Can someone please explain this...

Nope, Im saying you provided a poor example. Bell barely got 3 inches but yet, you somehow automatically declare he would have gotten a yard while running into a stacked box. Even neater.

They are also fortunate that running play worked in SD because they never would have gotten a time out called if it hadn't.

Nice but meaningless since we don't know what the situation was on any of those. Safe to say he wasn't running into a wall too many times.

I don't even know why this is debatable, when a defense is gearing up to stop a run, you should audible out of it, I dont care who the QB is. If you want to say it should have been a pass play to Bell, thats fair but I think trying to run with 8 in the box is poor play calling and has a low success rate.