Other mistake: When Ryan and Alex are first together in the hotel room, there is a gratuitous nude view of her getting on the bed. The body double used for this couldn't be more than 21, and her appearance is quite at odds with the character, who is pushing 40.
Suggested correction: This is pure opinion. Yes, it has been said that a body double was used in this scene. But within the world of the movie, there's no reason that can't be Alex. She reveals later that she's 34, and many women look absolutely splendid at that age. We see her partially nude in the very next shot, with no big discrepancy from what we saw from behind. It wasn't until after several viewings of this movie that I found out that this was a double, and even now that I know, it's still not obvious at all.
Other mistake: In the scene where Ryan Bingham is giving his self-help presentation to an audience in Miami, he is standing behind a podium that says Wichita.