The point of the comment you are replying to is that it would be rather unreasonable to assume that.
Dents are just a minor form of crumpling.
Exterior bodywork work is irrelevant to occupant crash safety performance on unibodies (or space frames, like the Saturn S series), because they’re non structural elements. They’re decorative. Soft metal is chosen because it’s cheap to produce, not because it’s a crumple zone.
Crumple zones on unibody cars today are made of much stronger steel than the body is, and the channels are in the unibody frame which are slightly inboard from the sides of the car.
If you hit the crumple zones of a regular car on the road today with a sledgehammer, they wouldn’t dent. You’d need to hit them with something imparting many thousands of times as much force, like a car.
The only safety benefit to soft body panels is pedestrian safety.