He was asking her questions during her deposition, which is a question and answer session, given under oath. He was nasty. He was sarcastic. He was obnoxious. He was doing everything he could to intentionally push her buttons to see how she'd react.
Well, he got a reaction, but one he never expected.
Her reaction altered his view of the case and actually helped to resolve her lawsuit shortly after she gave her pre-trial testimony.