Just before the Lincoln sedan arrives at the airport, the view through the windshield shows the rear view mirror has been removed; only the circular pad is visible. When the car is next shown at the airport, the outside view looking in, shows the mirror in place.
During the opening, the guard shoots the first alien. As the Invader's body begins to disintegrate, the dead mail truck driver's arm changes place.
The strange metallic cylinder floats in water thanks to a pair of visible wires.
When Swain is reaching through the fence and grabbing the cylinder, as he burns up the cylinder burned but the fence did not, even though everything the aliens touch when they burn up is supposed to burn with them.