Lady Krasaviza used her skates to crush her slave's body. She realized he was developing tolerance for the kinds of punishment she used on him. She did not want to be rendered impotent so she changed tact and she used her skates to trample him. They were more painful and he learned his lesson the hard way and since then, he as never tried to go against any of her wishes.
Mistress Divine Domino likes to get even when someone messes with her. When this guy pranked her, he did it just for the fun of it. He did not realize how it had affected her. He was just having fun. And that is what she was doing when she got her revenge. The mostress trampled him and enjoyed crushing and stomping him and jumping on him as much as she wanted.