Doesn't seem that controversial. A publisher commissioned a book about the films of Stanley Kubrick, agreeing that Kubrick would be able to veto publishing of the text if he didn't like it. He didn't like it, didn't sign off on it, and the book was never published.
From the article, it appears the big sadness for the author was he wrote back and said he was happy to work with Kubrick to discuss getting it to where he was more comfortable with it, Kubrick never responded, and then sent lawyers. That's all that's rough for the writer, here.
I don't know many artists who would enjoy the prospect of justifying their art to someone who was skeptical of its merit from the start.
Not saying Kubrick did the right thing, just that it seems very on-brand for most people in his position.