Earl's shirt is dirty from being pulled by the ostrich until he turns around.
Just before Earl thinks of being showered with the fire extinguishers, the green roller door is free of obstructions. Though as Earl grabs the first fire extinguisher and proceeds to run back to the door, the roller door is obstructed by several items.
When Grady first looks over at Burt in the backhoe's front bucket, Burt has his knife in his hand. In the next shot, with Burt trying to avoid the Shriekers' tongues, he is shown drawing the knife.
When Earl has some explosives in the back of the RC truck with a remote detonator attached, the antenna of the detonator is alternately facing backwards/forwards between shots.
When Earl's truck is being pulled by the graboid that bit the chain, there is something sitting on top of the case of explosives that is covered by a brown tarp which disappears and reappears between shots.
Burt says that the MRE rations have a shelf-life of ten years, which is incorrect. The actual shelf-life is three years under optimum conditions.
The "MREs" Burt has are actually emergency rations (they appear to be S.O.S food bars).
The full Moon, seen when Earl and Grady were camped on the rock outcrop listening to the coyote get eaten, is many times too large.
The Playboy centerfold in Earl's place is that of Debbie Ellison, Miss September 1970 and not Miss October 1974.
When Burt fires the high-powered rifle and the window behind him blows out, you can briefly see a crewman inside striking the glass with a ball-peen hammer to shatter it.
When the first graboid is blown up, parts of it are raining down on Earl and Grady. This is all coming from the side of the truck directly in front of Earl. Just as the "rain" is dying down a large chunk of graboid flies in from the left, the area to the rear of the truck, appearing to be thrown by someone.
When one of the graboids is blown up, the pieces of the graboid in the movie are clearly pieces of watermelon in reality.
Just before the final cut to black and credits, Burt can be seen walking into the matte painting area of the frame and his upper body becomes semi-transparent.
Between 1:22.24 and 1:22:30, a vehicle can be seen moving through the trees to the left (our left) of Earl. This defeats the isolation that's portrayed in the movie.
When they drive the jeep, shortly after throwing out the noisemaker-chain, you can briefly see that the image has been mirrored and the truck they're in has the steering-wheel on the right side as they zig-zag through the open fields, but in the closeup-view its a normal car.
When Burt accidentally shoots the engine block of the Jeep, the characters go to examine the damage. At the end of a long dolly shot following the group to the car, the camera stops and can clearly be seen in the reflection of the side of the jeep, to the right of the bullet hole.
Right after Earl grabs the fire hose, two shriekers push boxes away, revealing their puppet controls below.
When Burt is in the bucket of the backhoe and the Shreekers are searching with their tongues. You can see a puppeteer controlling one of the
tongues.
The movie is mainly set in Chiapas, Mexico, which is that country's southernmost state and covered in jungle and rain forest. However, the movie shows a desert setting inconsistent with the stated location.
When Burt is doing his personal log on his way back after the radio failure, he notes that it's 19:00 hours on May 14. Whether it's 19:00 GMT or 7:00 P.M. local time, it would not be dark, but in fact still rather light out.
Kate dates the Graboid fossil to be from the Precambrian era. However, there was no life on land at the time, meaning the Graboids would have nothing to feed on.
No explanation is given as to why the graboids would come be known in Mexico a few years after they came to be known in Nevada and not have been known in Mexico before.
Kate incorrectly refers to the Shriekers as "hermaphrodites". How the Shriekers reproduce would be considered a form of asexual reproduction. Indeed, Kate then says "they reproduce without having sex". The term 'hermaphrodite' refers to animals that have both sets of male and female reproductive organs. In the case of the Shriekers, in which they don't appear to have any such reproductive organs, they would be considered asexual.
The 50 caliber BMG or Browning Machine Gun cartridge was not based on a WWI anti tank gun. John Moses Browning took the 30.06 cartridge and scaled it up to 50 caliber for use against vehicles.
After Bert kills the Graboid with the chain hanging out of it's mouth, and he speaks with Grady over the radio, he signs off with "Over and out." As a survivalist, Bert should be aware that the correct sign off for a radio communication is simply "Out" and hat the use of "Over" implies a response is requested or expected.