“So signs of betrayal or a certain withdrawal were there already before she met your “friend”, they just escalated with him. Would you say that’s true?”

I would say so, yes. She did let me down multiple times and even didn’t do things she said she wants to and will.
I assume she was already more than full of my love and affection at a point was just waiting for an opportunity to jump into a new train so she didn’t feel like keeping the full pretense of wanting to help me anymore.
Why would she monkey branch towards somebody who abused and disrespected her and me both, whom she constantly criticized and knew nothing about though? That’s a mystery but I don’t think it’s the sign of a healthy mind.

“And also, you said she was making unreasonable demands on you, but you were too much in love to notice it. Could you give one example of such an unreasonable demand?”

Things such as expecting me to both work on multiple things at once while giving her my full attention and most of my day as she was well aware that I was barely getting a few hours of sleep a day for months and months.
Or blaming me for not solving the conflict between her and my “friend” in a proper way and for putting her through it even though she herself constantly tried to interact with him while he wanted nothing to do with her, I told her to stop and she herself said it’s hurting her and she should stop.