Continuity mistake: When Roy first encounters the alien ship at the railroad crossing, when the bright light comes on, he leans out of the truck window, and the right side of his face is exposed to the light. Therefore, it is the right side of his face that should have been burned. Subsequent shots show that the left side of his face is burned. (00:21:00)
Suggested correction: Roy shields the right side of his face with the hand holding the torch so that it's not exposed. His left side is not covered so it gets burnt.
How could the left side of his face get burned, if it's not exposed to the light?.
Continuity mistake: When Richard Dreyfus has his first UFO encounter at the railway crossing, all the gauges in his truck go wild and the contents of the glove box comes flying out. After the encounter finishes, and the vehicle's power comes back, Dreyfus starts the engine and drives off. Miraculously, the interior of the truck has tidied itself and restored the glove box contents to their proper place. (00:21:30)
Continuity mistake: The film starts in Muncie Indiana. There is a scene in the hills near the town. There are NO hills near Muncie, it's flat as a board. (00:24:30)
Continuity mistake: When Roy says to Ronnie, "I saw something last night that I can't explain.," and he bridges his arms across the door frame his forearms are parallel to the ground. In the following shot, when Ronnie straightens up, Roy's forearm points upward. (00:36:15)
Factual error: The aliens broadcast a series of pulses which are decoded by the scientists to be a longitude and latitude. In degrees:minutes:seconds, the longitude is 104:44:30 and the latitude is 40:36:10. These numbers are what the computer display shows and are what the scientists say (except for one slip-up in the hallway early in the scene where 104:40:30 is said). The scientists grab a globe and declare these coordinates are in Wyoming. Everybody and his brother (and the aliens) then proceed to show up at Devils Tower, Wyoming. However, Devils Tower is at around longitude 104 deg 44 min and latitude *44* deg 36min, not the *40* deg 36 min pulsed out by the aliens. If everyone had gone to 40 deg 36 min, they would have ended up in Colorado, more than a couple hundred miles south of Devils Tower, Wyoming. (00:46:23)
Visible crew/equipment: When the little boy is looking out the window of the farmhouse toward the sky to see the incoming spaceships (where he says "toys" rather excitedly), as the camera closes in toward him you can see the shadow of the camera/crane on the right side of the screen. The shadow changes as the camera zooms in. (00:49:55)
Continuity mistake: As the mom and her son run into the kitchen of their house for safety the appliances start to shake. In the first scene with the stove, all of the pans are shaken off the top, but when they come back for a close up there are pans back on top. (00:56:00 - 00:57:00)
Audio problem: Just before Toby closes his bedroom door while Roy and Ronnie are arguing, if you listen carefully you can faintly hear director Steven Spielberg telling him to close the door. (01:05:00)
Continuity mistake: After Roy fills their kitchen with shrubs, bricks, soil, and chicken wire, Ronnie takes their three kids out of the house and into their station wagon. She tells her kids to lock the doors, but the driver's side door lock is up (unlocked). When Roy walks around the driver's side to speak with Ronnie, the driver's side door lock is now down (locked). (01:10:05)
Other mistake: When Richard Dreyfus rushes to the street to grab the trash can as the trash truck is coming down the street, his family is the only one on the block that has their trash cans out. It's obviously trash day and many of the houses are yet to be serviced by the approaching trash truck. (01:14:30)
Continuity mistake: When Richard Dreyfuss is building the model of the Devil's Tower in his living room, behind him in the sliding glass doors you can see that it is raining, and when he turns around and walks to the door to look out, it is now sunny, and people are out side mowing the grass and children playing. (01:15:40)
Continuity mistake: When Ray first arrives at Devil's Tower and stops the station wagon, the broken fence post resting on the hood changes positions between shots. In the view of him through the wind shield, the post is lying straight, parallel to the length of the wagon. In the next shot, it is suddenly at an angle, even though the car hasn't moved. (01:21:30)
Other mistake: In the climactic scene at the end of the movie when the alien mothership flies over Devil's Tower and the base, there is a shot of the mothership's shadow creeping along the ground, enveloping the shadows of the crew there. It's a dramatic shot, but since the mothership was not between the ground and the light source (the stadium lights of the base) it should not be blocking out the light, or creating a shadow. (01:55:08)
Other mistake: One visual that has always bothered me that I could not find in your list were the scenes when the mother ship first appears. It's enormous scale appears to dwarf Devil's Tower and the whole surrounding area actually, but when it moves over to the "landing strip" area and begins to rotate 180° (right-side up?), it suddenly seems to shrink to a much smaller size and mass during the slow revolution. On its originally-seen scale above/behind the tower, one would think that either the great ship's outer prongs would have been torn off, or more likely the impromptu landing site and most of Devil's Tower would have been destroyed as the huge craft rotated itself. The visual scales just do not stay consistent throughout the film's climactic final act.
Continuity mistake: During the scene at the landing site the number of people on the landing pad varies dramatically from shot to shot.
Continuity mistake: Before Roy takes the top of the clay-mountain off, the model has smooth sides. When he is about to tear it, it swaps to striped sides.
Factual error: Early in the movie there's a scene that takes place at the FAA air traffic control center. As the film's other scenes are set in Muncie, Indiana, this ATC center is presumably (and correctly) in Indianapolis, yet, after the UFOs nearly collide with the TWA and Air East flights, the controllers are talking about "restricted area 2508". The "real" R-2508 is actually out in California/Nevada.
Revealing mistake: When the UN team arrives in the Gobi desert, there's one shot where the helicopters and trucks are parked. They're supposed to be moving, but you can tell from the way the flags are moving that the wind is only coming from the helicopters.
Revealing mistake: In the scene where Ronnie cuts out a newspaper article about the UFO sightings, the night after Roy's first glimpse of the UFOs, two identical articles on Star Wars (1977) are on either side of the UFO article.
Suggested correction: The articles aren't identical, they are continuous. I read them. Only the title, "wars" is identical.
Factual error: When Barry first appears in the middle of the road, you can see the constellation Orion in the upper right of the scene. From mid-northern latitudes, Orion is visible in the evening from October to early January and in the morning from late July to November. The scene looks like a summer evening and if it was the morning Orion would not be that high in the sky.
