It's showbiz. I'm sure plenty of people in the industry act like divas frequently. Look at what happened with Christian Bale going off on the set of Terminator Salvation. Is there really any excuse for that? It was definitely embarrassing, and the movie was a disaster. But it didn't keep Bale from getting an Oscar eventually and still having a fairly strong career afterwards.
David O. Russell was apparently so bad on the set of Three Kings that George Clooney punched him. He's apparently burned bridges and made enemies out of a lot of actors, but he's still getting big directing gigs.
Also, two words: James Cameron.