Visible crew/equipment: In the bar fight scene, the camera crew is visible right after Lefty hits one of the bar patrons.
Continuity mistake: Gus Soltic at the beginning of the movie pours ketchup on the eggs. When he's done, he moves away the bottle in one shot, but it's still vertical above the eggs in the next shot. (00:02:00)
Revealing mistake: At the end of the film, it's obvious the ground that Phil falls into is just some mats dressed up in fake snow.
Other mistake: David is trying to locate the beast through a map of the city - for some reason, since he already located it before. Problem is, the movie is set in Missouri but the map he's looking at on his bed is a map of Los Angeles (you can even read "Granada Hills"). Similar mistake a few minutes later in front of the sewers; you can easily read "Monterey Park" to the right of a different map he props against the wall. (00:37:15 - 00:38:35)
Visible crew/equipment: When the main character and his family are first seen making their way to the train, the rightmost one in a row of three eerie blonde pageboy-haired children keeps looking into the camera. Generally, throughout the movie, there are plenty of instances of child actors looking into the camera, mainly young Malcolm (Lorenzo Aiello). (00:05:15)
Continuity mistake: When Hawk and Ranulf are about to enter the gateway in the forest, Hawk raises the "mind sword" which lights up bright green. Then cut to a shot from behind and Hawk still has the sword raised in the air but there is no longer any green light illuminating the forest. (00:29:12)
Revealing mistake: In this very-low-budget but star-studded flick about UFO contactees and cattle mutilations, Jan Michael Vincent's semi-auto handgun runs out of ammo during a firefight after firing only 3 rounds (the slide locks open, indicating the magazine is empty). Without reloading or racking the slide, Vincent continues firing 5 more rounds; but we see again, in close-up, that the slide is locked open, indicating an empty magazine. (01:00:55)
Other mistake: Tommy's got blood coming from her left nostril even though Rosa only twisted it, she didn't do anything hard enough to cause a nosebleed.
Factual error: The Hillman Minx car seen picking up Brits at Conchin railway station is at least a 1945 model. The film is set in 1943.
Continuity mistake: Kenny must be fast. He's disguised as the female assistant at one point then minutes later he's disguised in the Groucho Marx costume.
Suggested correction: It's not a full costume. Kenny steals the mask and what looks like a small waistcoat (leaving even the hat). It's not implausible that Kenny made a quick change (probably after killing Ed) to formal wear (which isn't what Ed was wearing). After Ed's murder, Kenny-as-Ed appears briefly only from the waist up (showing only the stolen mask and waistcoat), and then doesn't appear again for quite a few minutes, more than enough time to change to the formal wear.
Continuity mistake: When Mickey gets into the '57 Chevy to "test drive" it, there is no gear shift lever on the steering column. The camera then shows him buckling his seat belt, and when it returns to the previous angle, there is that missing shift lever.
Visible crew/equipment: When the survivors of the cruise liner sinking approach the ominous ship, it's supposed to be deserted, but as a window opens, a person's arm holding a stick to open the window is visible.
Factual error: There appears to be a pickup truck parked by a barn in the background when Steve McQueen is standing by his horse, talking to Linda Evans. (00:19:00 - 00:20:00)
Revealing mistake: Linderman refuses Clifford's offer to be his personal bodyguard from Moody's gang, and leaves. As Clifford walks by the students practicing their violins, playing Mozart, their bow movements do not match the music.
Factual error: When the Peanuts gang got to Victoria station, Travel Center is spelled the American way. Since it's England it should be "centre" (00:24:55)
Continuity mistake: When Cole and the halfbreed duel with knives, the fabric they hold in their mouths as a tether keeps flipping over, meaning the end of the cloth hangs out the left side of the mouth, then the right, and left again - several times for both actors - even tho the fight is continuous and they make no moves that would change this.