I didn’t reveal any confidential information, but when I was asked by a colleague I knew - as a friend - in another department to be their observer in a disciplinary process I did so because I felt that they must be innocent. I got far too invested in it emotionally and it caused me a great deal of stress. I was not thinking straight for a while.
After a while it became clear that the complaint was more than justified and I was really upset at being played in the manner I had been.
I suspect Dr Choc felt / feels the same and I pity him.
I'm sorry you had to go through that. I feel sorry for him too. It might be unwise, but I feel I'd have been tempted to do the same for a trusted friend.