I finally got around to checking out the movie in HD again. I only watched the Hoth section so far, but I've noticed a couple differences between the pattern and the original.
1. The back seam on the arm is set in the wrong place. The seam on the original comes out almost right at the yoke seam on the back. The one on the pattern is distinctly lower. That's a really complicated alteration to make. It looks to me like the yoke seams are in approximately the right place, but could maybe be made 1/4" to 1/2" lower. That still leaves the seam on the sleeve about 1" too far in to meet in the correct place. The sleeve pocket may also have to be moved slightly to keep everything positioned correctly.
2. The top pocket flaps are not set into the front yoke seam, they're folded over and topstitched exactly the same as the bottom flaps.
Also, based on how the jacket was wrinkling, I'm inclined to say it was a wool blend, not 100%, but I can't say that for sure.