Did Sean and Oliver not get along on the set?
I've read a lot of things about these two and they don't seem to like each other very much. For example, Oliver Stone called Sean a "f**king loser" and Sean said:
Discussing Oliver Stone: "I think that his basic pig nature keeps him from doing the best of what he ought to do. And it keeps him from being someone I want to run into."
So, they obviously didn't say these things before the movie otherwise they wouldn't have done the movie but did they fight a lot on the set or something?