This guy misquoted mistress Sofi so badly that she could not let it go. She had to punish him so that he learned to quote people properly. He had sort of ruined her reputation because of how badly he had done it. It gave people a very wrong impression of her and she was not impressed by it. So she slapped the shit out of him to make him be careful next time.
Mistress Sofi is the kind of person you do not want to mess with as this guy came to learn. And that is why she had to make sure things changed. The mistress faceslapped him after she had facesat on him because she felt that facesitting on him had not done what she had intended for it to do to him. But after the slap, she knew he had gotten the message.