I don't know why you're having a go at him, Pike. At least the information he is sharing are drawn from conclusions HE came up with...
Anyways, I sort of see where Brandaddy is coming from. I used to think that a true auteur needed to have contributed to the original script. But I have grown out of that. What Mark indicated was right. The director is the most powerful person in the process of film making. It's up to him/her to
reinterpret the screenplay they are filmmaking from. And they can also change certain things they disagree with within the script as well.
A good example of this is Mary Harron's
American Psycho. She came on board with Christian Bale in mind for the titular role. However, before she had shown any interest in the film, the studio execs had Leonardo DiCaprio in mind for the lead with David Cronenberg or Paul Verhoeven possibly directing. It was originally going to be a straight up adaptation into a conventional stalk 'n' slash horror show. But Harron's version reinterpreted the script to making it a black comedy with biting satire on the 80s yuppie culture.
An auteur, at least to me, is all about the thematic flow between a director's work. Look at Stanley Kubrick's work and see how each of his films flow into one. Same with Christopher Nolan. I won't go there because I have exhausted that man's name, and I think people realise how beautiful his work is anyways. An auteur can be identified by the visual process of his/hers film, too. John Woo and auteur are rarely mentioned in the same paragraph, but I consider him to be one. Most pretentious people wouldn't admit that because his films tend not to communicate well with the 'cerebral'. However, if you look at his signature shots and recurring themes, you can make a case for him.