Even though the story takes place during the course of one night, the TV GUIDE Magazines at the checkout stands change periodically.
A re-used shot of blood on the light-bulb in Danny's office is used. The blood stain starts small and gets bigger as the blood drips. The small stain is seen a second time near the end of the movie.
Jennifer's pants' pleats are reversed in one or two scenes. This suggests the character was assigned two different, non-identical pairs of pants. The majority of the movie the pleats are facing away from the zipper.
The clippings affixed to the wall calendar at the customer service desk change between shots. This is noticeable while Jennifer is trying to get a hold of the police on the phone.
When Joe's body is seen on the conveyor belt and then goes in reverse, the head falls off and rolls to the side. But in the long shot of him going back up, the head is still near the shoulders.
When the telephone box is knocked over, the base is solid wood, with a metal foot at each corner. There is no way to fix it to the ground, and nowhere for cables to run.
When Jennifer tries to smash the supermarket's front entrance door's glass with the fire extinguisher, it clearly makes no metallic or any significant hard sound as expected, plus it makes hardly any sound at all when she drops it onto the floor. Indeed, the extinguisher looks totally fake.
Jennifer and Linda restock Diet Pepsi cans in a display. From the sound, it is obvious that the cans are all empty.
Jennifer hits someone on the head with a green bottle. From the rounded bottom and the noise of the impact, it is clearly a plastic PET bottle. When she throws it on the floor, though, there is the sound of shattering glass.
Near the end of the film, Jennifer deposits change in the payphone to dial 911, which she does not need to do. All payphones in the United States are (or were) legally required to connect a 911 emergency call for free.
When Dave's head is sliced on the meat slicer, it is clearly a fake head.
In the scene where Alvy Moore and Tom Lester enter as police, a bearded crewmember is reflected in the glass doors.
When Jennifer gets off the phone with Craig and leaves the office, the camera crew and dolly are reflected in the glass.
Randy's body is swaying back and forth, but his feet are stationary, indicative of him standing on something and not really hanging on a hook.
When the butcher gets his face stuck on the hook and hangs from it you can see a wire next to the hook holding him up.
Stuntman visible when "Bill" turns over the phone booth with Linda inside. He has a different body type and a full head of hair.
The DVD box design lists Renee Estevez as Jennifer, when in fact Jennifer is played by Elizabeth Cox, and Renee Estevez plays Jennifer's co-worker, Linda.