Deliberate mistake: The aliens fire on a bell tower with a clock on it. In the next shot a different building blows up. (01:17:15)
Deliberate mistake: As the alien spaceship attacks a bomber we see it superimposed through the windshield. The pilots never react because they're not actually seeing it and are poorly directed. (00:57:10)
Deliberate mistake: As the saucer lands on the White House lawn the aliens walk out and fire on some soldiers, killing them. A few shots later we see them walking backwards into their spaceship as the film is obviously run backwards. (01:16:25)
Deliberate mistake: Two trucks with magnetic interference units on them are shot at by the aliens and the exact same sequence is used again three shots later as they shoot at them again. (01:18:35)
Deliberate mistake: After the alien ship destroys the bomber, Dr. Marvin picks up the helmet and they all start to run back to the car. In order to save time in repositioning the camera they start out 50 feet behind where they just were in the previous sequence and run back to the exact same spot. (00:57:50)
Deliberate mistake: After the aliens announce their intentions Dr. Marvin meets with Carol back at their hotel room. He tells her that she must take a flight alone back to Palm Springs and then leaves the room. In the end of the scene she picks up a copy of The Evening Star, which is an obvious prop as it has no date on it. (01:08:50)
Deliberate mistake: As the Marvin's approach "Operation Sky Hook" they hear the UFO above. Out the rear view window we can see the same sign and background they passed several minutes ago when the doctor started making his tape recording. (00:05:15)
Deliberate mistake: As the alien ship attacks and destroys the bomber with it's ray gun we see stock footage of a different WWII bomber being destroyed by the German Air Force. (00:57:15)
