Thanks for sharing that. The specificity of details as outlined in that lawsuit are not commonly known rock history. The playwright in my eye lifted things wholesale from the book.
Here's my theory: They might not have been commonly known before the memoir was published, but the plaintiff was reporting them as fact, as if those exact words were said, putting them in quotes.
So didn't they become part of "music history" the day the memoir hit the bookstore?
If, for example, one of the musicians in real life tried to choke the music producer, that choking is part of music history, it would seem.
The plaintiff (the music director) was representing them as facts.