That's one thing I noticed on all the Thief screenshots, as well as Roger Rabbit entirely... the cel animation is so perfectly crafted. Even in the best Disney cartoons (even Snow White, Bambi, and Fantasia), there's a lot of mistakes (many corrected for DVD).
But on those two films, I can't see a speck of cel dust, any uneven cel painting, or reflections. Not even film grain. Although, I've read that when you deal with animation (drawn or models), you can fully expose a frame with absolutely perfect exposure and lighting. Thus, a very, very low amount of grain texture.
In sort of Machievellian terms, yeah, he'd go over budget and over schedule, but the end result justifies it.
I think Williams would have been able to avoid some of his later problems by just cranking out a handful of excellent, but quickly made films in the 1970's. Even if they were not as polished, as long as they made enough money... this is how Charlie Chaplin was able to gain independence. He could spend 3 1/2 years on a 80 minute film like City Lights, with almost 300 takes for one scene... having months out of production... rehearsing on film. But no one could say no because he was in full control.
He should have had a different contract, too. After the success of Roger Rabbit, he should have been more forceful on the terms - like being allowed more time and money. Honestly, with three Oscars in hand and right off a huge blockbuster movie, what's 7 more years in production instead of 4? Considering the money being poured into crappy movies in the 1990's, as well as good ones... surely "Thief" wasn't eating up too much money. The War Machine sequence cost a quarter of a million and it was the most complex part of the movie - I can't imagine the whole production costing more than $30 million. Any idea on the costs?
Who Framed Roger Rabbit cost $70 million, but "Thief" didn't require all those practical effects, compositing, live-action shooting, etc.