Just eyeballing 3000, s3.9.4.5, regarding "safe" locations of wiring in walls. What constitutes free movement of a cable?

I assume the intent is to allow anything penetrating the wall to deflect the cable instead of cutting it, not many contractors i know that leave that much slack in wiring, or hole saws/spade bits that are designed with deflection guards.

Anyone seen a ruling on this one?