*SPOILER ALERT

When it gets to the part where Metroman is "trapped" in the observation tower, watch close. It shows him on one scene with only metal behind him, and red paint on the sides. Then, in another scene, it switches (red paint behind him and metal with red foot prints on the other).

Then, swtiches again.

When it get's to part when Roxy and Megamind are went back to the old school house (Metroman's hidding place), Metroman tells them how he faked it with a flash-back. In the flash-back, watch behind him again. In the scene at the begging of the movie, the paint behind him was switched.