Lady Scarlet wanted her assistant to learn that she was not going to let him get away with major mistakes like he had made. She had forgiven him once but she was not going to do it again. And so she head crushed him to make sure that he learned not to mess with her again. He was in pain as she tried to pump some sense into his head.
Lady Scarlet had gone to this guy for advice and he gave her the wrong one. She knew he had given her the wrong one as she gave someone else the right one and it was on the exact same thing. He stood to benefit by giving her the wrong advice but luckily she found out before using it. And she went back to him and she punished him by trampling and crushing his head and his balls.