Can a district attorney threaten and question an alleged victim that is a minor without a parent present?

My daughter went to court for domestic assault from my fiance. She told the court associate that it was both of their faults because she had initially assaulted him and they were equally combative. This is not what the Assistant District Attorney wanted to hear, once we were brought into his office, he began with a speech that basically he is God of the courtroom and not even the judge can tell him what to do. He further stated he does what he wants when wants and can charge anyone he wants with whatever he wants. After this speech, He asks me if I was going to remain engaged with my fiance. I answered yes, my daughter asked if he could come home. The D.A. ordered me out of the room. He questioned my daughter and threatened her with a felony if she did not agree with what he said. She tried to tell him the truth he did not want to hear it, is there anything I can do? She is scared to death of him because of his actions and the threatening manner he carried himself.