Other mistake: In Assault, Pyscho's mouth doesn't move when he keys in the next objective after you destroy the last AA. You can see this on the crane with Pyscho on it or binoculars.
Plot hole: Pyscho says that he will provide support in the 2nd level, but there is no support at all.
Trivia: In the first level, there is a balcony behind the command post. In the food shack, there is a radio on the ledge. Use it, and it will talk about why North Koreans evacuate the island of some volcanic activity.