Other mistake: When the US Student tries to get from the west to the east, one can see Volkspolizei and Kampfgruppen on one side of the wall and Westberlin Police on the other side of the wall. The camera pans, on the right side, brickies are busy with the wall (which should be the east side), a couple with child is running (why? They are already on the other side), camera pans further and shows the student pushing his bicycle. In the background are now NVA soldiers and an East German tank (see the markings). Isn't this the west side? It is definitely not the side the brickies are on, and the wall was built from the east side. I guess the soldiers and the tank are on the wrong side of the emerging wall.
Other mistake: In several scenes in Tom Hanks' home the TV has a set of rabbit ear antennae, but to the right of it is an antenna rotatory control for an outside antenna, I would think in Brooklyn rabbit ears are all that was needed.