If I remember, he sold his story. Got paid. Then wasn't happy with the "creative liberties."
The movie is generally considered to be excellent. It was critically acclaimed and received five Academy Award nominations. The movie is not my cup of tea, however. I watched it once, and wouldn't care to watch it again.
BTW I was granted an audition to be an extra, but it was very last minute and I couldn't make it work with my schedule.