It's totally understandable the child feels embarrassed. Standing up to someone like that is a difficult thing to do.
I don't know your relationship to the child, but if you are an adult and in a professional capacity, you would have some duty to look at what you do with that information as the staff member's behaviour is abusive (in my opinion and part of the world).
Maybe the staff member has done this before? Maybe there are already complaints about them?
But, no one can force the child to report anything. Like others have said, ittaboit supporting them
I think the context of who you are to the child is important. If you are a professional, I would look at your policies and act accordingly. If you are a child, then it's about how you support another child - you don't have the same responsibility at all as an adult in this situation.