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.
Candice's hair changes from being loose when she lies down on the couch to being tied up when she wakes to the sound of the air strike.
Jarrod's hair changes lengths when walking down the hallway before meeting Walt.
The color of Elaine's pants change after Jarrod and Terry leave the apartment. Evidence of this is seen when Terry comes back from Walt's apartment.
After a nuclear explosion downs the alien ship, moments later we see the overhead view of two choppers over the city, and not a single sight of damage over what should be rubble and not a city.
Towards the end of the movie as the camera is showing the attacks on various other major cities some air conditioners are obviously moving (fans turning) although the power is supposed to be gone.
While Jarrod is taking photos on the rooftop, the camera has a sound of film advancing, but digital cameras don't have that feature.
A TV is shown with an Emergency Broadcast System alert. The EBS was replaced by the Emergency Alert System in 1997.