You all remember the famous opening sequence of "Knots Landing" in the first season with the aerial footage of the famous cul-de-sac. For those that do not, here's how it went:

The sequence begins as the camera zooms out of the beach, then fades into the familiar cul-de-sac with the title and the camera zooms in on each house of the cul-de-sac revealing each couple. After the cast is shown in the cul-de-sac road, the camera zooms out again.

Here's the blooper: When the camera zooms in, take a good look at the road above the cul-de-sac and you will see a bunch of cars go down the road. When the camera zooms out again, What do you see? The same group of cars GOING BACKWARDS! You know the film was reversed in order to zoom out again.