Maximus WCA face to face

I completed my esa50 in June 2016 and had my face to face Wca 22/12/16. I was asked before we went into the room if I would mind an observer in the room. She was a new member of staff who had just completed her training and was sitting in on WCA. She would observe only. However during the ordeal which was one and a half hours I noticed her making notes and she prompted my interviewer to ask if 'I was ok with social media' & would I like to work in the future.
I didn't want to refuse an observer as I didn't want to be looked upon as being obstructive. I found that my interviewer was finishing my answers off, was clearly not interested in any historical problems I had and still have now. He was quite precise on how often I have problems, how long episodes last , what medication I take, although did not want to see my medication or visually check problems I have with my feet, which leave me unable to walk without being in excruitiating pain. I personally feel I was like a rabbit in headlights, and the constant questioning was too much for me. I wish I had taken notes in with me. This is the first face to face Wca with Maximus. I advise other members to take notes and be more prepared than I was. Do you think I was right or wrong to have an observer? I also had my interview taped and at no point is it recorded that I had an observer in the room. Would this make the tape void?