This mans did not just say "don't be petty"! I would immediately give him the evil eye and tell him to never speak to me like that again. And if he said anything other then an apology, I'd straight up leave and cut all ties.
As someone how has been in d/s relationship before, Misa is (although weird circumstances around how they met aside) is an example of a good and healthy d/s. Manager is showing all the red flags.
Hope she gets what's coming to her