During the first scene in which the crew is escaping in the truck, in one shot, a dent on the right side is present. In following shots, the dent is gone. During the second escape scene, we see the side-swipe collision with a tree that makes the dent.
In the initial escape scene in the truck, the passenger side mirror reappears on the truck after being torn off by a tree.
When Mike Rogers is on the couch and about to receive Travis Walton's phone call, his daughter changes sleeping positions on his lap between shots.
When the aliens are about to begin doing experiments on Travis Walton, the sheet they pull over his body moves up and down between shots.
In the logging scene, during the lunch break, Mike Rogers is shown sharpening his saw chain. He's using his file at entirely wrong angles (would ruin a saw chain), and is filing the same tooth way too many times.
In the logging scene, Mike Rogers is shown felling a tree, calling "TIMBER". As he pulls his chainsaw away from the tree, the bar is on the "notch" side of the tree (in the direction the tree is falling). That's where one makes the FIRST cuts to fell a tree. The final cut is the "release" cut, on the other side of the trunk.
When the logging crew is encountering the alien craft, the radio in their truck goes haywire. There's a shot of one of the crew trying to adjust the radio, depicting a Philco AM radio. The radio is appropriate to the vintage, but Philco radios were the "factory" radios for Ford vehicles, and the truck used in the story is a Dodge.
James Garner turned on the tape recorder by pressing the black button but in order to record the black and red buttons must be depressed simultaneously.
At one point, Henry Thomas' character is seen wearing a shirt with the cover of the "Grand Illusion" album by the rock group Styx on it. The events in this movie take place in 1975. The "Grand Illusion" album wasn't released until 1977.
In the first restaurant scene, Bobby Cogdill is seen wearing a T-shirt with the cover of the "Rumours" album by the rock group Fleetwood Mac on it. The events of this movie take place in 1975. The "Rumours" album wasn't released until early 1977.
In the logging scene, one of the loggers is shown pulling the recoil rope to start his chainsaw. But the sound effect is of an engine being started with an electric starter, not a pull cord. In fact, all one-man gas chainsaws have recoil start.
The beeping of Mr. Walton's EKG does not correspond to the graphic.
During the alien abduction scene as Travis Walton is getting his clothes ripped off, a man wearing a shirt is seen on the left side of the screen, he's the one ripping off Travis' pants.
In many of the forest scenes ferns can be seen growing. Ferns do not grow in Arizona but they do grow in Oregon where the movie was filmed.
During the meeting at the local church, the sheriff informs the community that Mike Rogers and his crew flatly refused to take a lie detector test. None of them refused. Mike Rogers specifically told the sheriff they would think about it.