Crew or equipment visible: Shadow of a helicopter following George Webber when he drives on the highway.
Continuity: The level of George's brandy when he is drinking at the bar. He tosses it back and the drink is very nearly gone but when he smiles at the blonde sitting to his right there's more in the glass.
Continuity: When George and Samantha are looking at each other through telescopes, the scopes are seen at angles away from each other, which wouldn't be possible if they are looking directly at each other.
Revealing mistakes: When looking through the telescope the picture moves around as if being moved by George. But when it shows George looking through, his hands are behind his back as if he has made no attempt to move the telescope.
Factual errors: When Samantha Taylor uses the operator to phone home, she asks for a number in the 275 prefix in LA (which was all 213 area code at the time). Although George Webber home is clearly located in Malibu, the 275 prefix in the late 70s was located in Beverly Hills. Additionally, the film doesn't use the now standard convention of unassigned "555" prefix phone numbers, and gives an entire seven digit number - 275-0187.