Other mistake: According to the plot, no life is possible in the Northern Hemisphere by the time the film is set. Yet, when the sailor who has been sent ashore to look around the San Diego refinery enters the premises (more precisely, when we see the smoking-prohibited sign on our right and his left) a bird can be seen flying in the upper left-hand corner of the screen.
Other mistake: At the end of the movie when the family is on the bed, supposedly dead after ingesting suicide pills, you can see the little girl breathing as the camera pans away.