People with just a little bit of power very quickly tend to forget its limitations. They might get so used to abusing it, cajoling people, throwing around threats and insults that they cease to consider the possibility that someone might get up and leave, or, even worse, simply refuse to be threatened.
A teacher shared a brilliant bit of malicious compliance when an abusive and ambitious principal tried to make him teach courses he wasn’t trained to do. When he refused, the principal mockingly suggested that he look for a new job and was unpleasantly surprised when the teacher decided to take him at his word.