So a large adult hitting a small child is equal to the child hitting the adult?

Power matters. In the event of a (non-physical) conflict, a rich person has options - they can file a lawsuit; they may be a friend of the owner and could get the employee fired, or if they're powerful enough to pressure the employer; the legal system usually sides with the more powerful person; etc. etc. etc.

Punching isn't just punching if it's not a fair fight.