In the scene after Officer Hallet (the police man) leaves Sally's store and he and Sally begin to talk, you get a close up of his face. Both his eyes are blue! later in the movie he says he has one eye blue and one eye green. How is that so?
It is true that all babies are born with blue eyes, and they change as they grow older. But this still isn't really a slip up, he was flustered at the time. Also, its alot easier to say 'I was born with it' that 'well, I was born with blue eyes, but, lo and behold, one of them changed, and I'm still waiting for the other to catch up!!'
he most certainly did not say he had contacts. he said he was born with it. but did you ever think about the chance that the lighting on his eyes made them both look blue. my eyes seem to change color with what i wear.
Sometimes the lighting can get in the way of the real colour of his eyes. They would have done this on purpose so you didn't make the connection on who he really was too soon.