Visible crew/equipment: When the spheres fly through the air you can see a "dot" following which is the camera.
Continuity mistake: At the end of the movie, when Tim walks through the double doors, there is a toilet in the background which wasn't there in the previous scene. There was a table in its place earlier.
Visible crew/equipment: When they show all of the spheres hanging from the ceiling in the room near the end, you can see the matting that they used to hang the balls from in clear view of the shot.
Revealing mistake: During the opening, where we see a new Tall Man emerge from the portal and toss his decomposed body from the second movie into it, the actor's reflection is visible in the metal portal poles as he waits for his cue to 'materialize' in the room.
Revealing mistake: When Reggie and Tim the sheriff's son are in the funeral home and get confronted by the two black women, the silver ball comes to attack and kills one of the women. Tim saves the day with a revolver, but when he spins the cylinder before firing, you can see all of the cartridges in the gun have already been fired: dimples in the centre of each casing.
Continuity mistake: The beginning of Phantasm III starts with a flashback from Phantasm II. The car being driven in the flashback is a 1971 Plymouth Hemi 'Cuda, with four headlights, two distinctly separate hood scoops, and a hardtop. In Phantasm III, the car is a 1970 Hemi 'Cuda, with two headlights, a single Shaker hood scoop with dual openings, a "Hemi" stripe, and a convertible. It's supposed to be the same car, and in the flashback sequence it's easy to see the differences.
