Right after the aliens land, Terry walks toward the window and his Superman tattoo is visible on his right upper arm. However, in a previous scene, when he is walking to the swimming pool bar, the tattoo does not exist.
When Terry pulls back the blinds and says "There's something down there," the camera cuts to a foggy street. One of the giant aliens is visible for about 2 seconds, but the aliens don't actually arrive until later in the movie.
When Oliver sees the nuclear missile hit the alien ship through Terry's telescope, there's a huge flash that makes him scream in pain. The eye he'd been using to look through the telescope would permanently blinded, especially when the light is amplified through the lenses.
When the large alien crushes the Ferrari that Terry and Denise are in, the alien crushes the passenger side, presumably killing Denise. However, shots of the car just before it's crushed and afterward show that the top of the passenger side is empty. Even when the car is lifted up and the destroyed passenger side is fully visible, there is no remaining trace of Denise when there would be.