From what I learned topping from the bottom implies that the submissive or slave is trying to dominate the situation in a less domineering matter. The sub or slave may try to push the Domme to do something she isn't comfortable with. Other examples could be the sub or slave trying to persuade the Domme risk her life, go against her integrity, make insincere promises, and selfish intentions. You have to be careful for guys like that. They are usually easy to spot but some are getting smarter. Follow your intuition!