I'll make some general comments about the script and Tony Gilroy's writing style. There are stylistic choices that are very effective in Gilroy's writing. The whole double dashes in both dialogue and scene descriptions that he does really creates a great forward momentum.
Another effective thing he does is to have brief descriptions in the parentheticals, like this:
MICHAEL: What’s my time frame here?
ZABEL: For you? I don’t know. I didn’t think it was gonna be a problem. (Michael’s silence says it is) I’ll ask.
The alternative would have been to add an action line describing Michael and then back to Zabel's dialogue. Maybe that's another “rule” that he breaks, but here it works.
Then there are other choices that for me don't work as well or at all. I don't care for the “Michael getting out of the car.” instead of the more active “gets” like we're all told is the “correct” way of writing in a screenplay for spec purposes. His choice, of course, especially since he's the director as well. But not for me. It slows down the read, in my opinion.
Then there are places where there is way to much inner dialogue and unfilmables going on. Like this:
“MICHAEL’S FACE as he walks. And later on we’ll understand all the forces roiling inside him, but for the moment, the simplest thing to say is that this is a man who needs more than anything to see one pure, natural thing, and by some miracle has found his way to this place. The wet grass and cold air and no coat -- none of it makes any difference to him right now -- he’s a pilgrim stumbling into the cathedral.”
That's beautifully written and I wish that would have translated onto film better. I have to watch the film again, but from what I remember, this scene was a bit confusing because all it was was George Clooney walking out in the field with the horses and then his car exploded. He's a good actor but come on, nobody can act out what transpired in the character's mind at that moment. Again, it's Gilroy's choice as a writer and director, but that was one of those moments that didn't translate properly to the screen.
The biggest reason is that it happens so early on in the film. This is on page 16 in the script. Had this been later on in the story when we had gotten to know this character and his plight, then it would have worked better. We would have understood what was going on in his mind, we would have put two and two together and understood why he needed that moment of solitude and nature.
Watch
this scene out of context, and it makes no sense at all. Watch it at the end of a two hour journey and it not only makes perfect sense but is also heartbreaking and feels earned, as in: the filmmakers has earned the right to give us this scene without any dialogue whatsoever, relying only on the actor's expressions and actions to tell us what is going on, and we understand it because of what preceded it.
I realize this Michael Clayton scene is a teaser of what's to come, but it does more to confuse the story than create intrigue, in my opinion. That's a small gripe with an otherwise enjoyable read.