Continuity mistake: When Pinhead is just about to start killing everyone in The Boiler Room nightclub, a man catches the first hooked chain that Pinhead unleashes. Yet when you look closely as you see the man holding the chain there is no hook, but a piece of wire.
Continuity mistake: In the scene where Pinhead is in the church, he stands behind the table, and the candle to the right of him is straight. He then pushes the cross off the front, look at the candle, it is now on a slant then in a split second the candle is straight again as if it had never been touched.
Continuity mistake: In the first hospital scene, where a kid dies by the hook-tipped chains in the operating room, there is a point where his head just explodes. Later, when Joey opens the door, for a second you can clearly see the kid's body, still with a head.
Revealing mistake: When Pinhead is killing the patrons at the club and they are running away to try and escape, you can see some of them laughing instead of screaming like they should be.
Continuity mistake: At the end of the film Pinhead tricks Joey into giving him the puzzle box by posing as her dead father. As soon as she hands the box over he takes a knife (or sickle or whatever it is) from his belt with his left hand and poises to strike. Then it cuts to a shot from behind and he's now gripping the knife with his right hand.
Deliberate mistake: As Joey is running down the street and having things blow up all around her, you can see other people walking on the sidewalk not reacting to the destruction around them, even when something blows up just a few feet from them.
Deliberate mistake: Joey finds Channard's photo of Capt. Elliot Spencer in the closed art gallery but Kirsty stole that photo and gave it to Pinhead in the second film, where it was left on the floor of Hell. Also, all the sketches of the box were amongst the things from Channard's institute but those pictures and the other similar ones were from Dr. Channard's home collection. They were never kept at the institute.
Suggested correction: It was actually in a room in the institute. Not hell. Easy enough to retrieve it.
Revealing mistake: After Joey runs from the club into the street and a car swerves to avoid her, it hits a lamppost which causes sparks; but look closely and you can see that the sparks appear just a split second before the car actually hits the post. The sparks were rigged and set off a second too early.
Continuity mistake: At the end after Pinhead has 'absorbed' Elliot and Elliot pushes through to tell her to work the box, her hands are clean. Then she reaches for the dropped box and her fingers are bloody, causing her fingers to slip on the front of the box and stop her working it.
Continuity mistake: In the scene where Joey goes to meet Doc at the Boiler Room and drives her car past his, you can see Doc's car door is open. When Joey goes to Doc's car, that door is shut and she opens it to look inside.
Continuity mistake: One of the chains reaches from the sewer and grabs Joey by the sweater during the chase scene. Every time the chains are used in the other films, they are incredibly accurate. One grabs Frank by the hand, as he grabs for Kirsty in the first film, and another effectively blocks Kirsty's way in the second, but now they can only grab Joey's sweater. [Pinhead deliberately makes the chains miss because he's just trying to intimidate Joey at this point. He can't kill her until she gives him the box.]
Continuity mistake: When Pinhead raises his blade to kill Joey, it's in his left hand. Suddenly, he's transported to the room with Elliot Spencer, and it's in his right hand in the next shot.
Revealing mistake: When Joey stumbles into the church, there are a few wide shots where you can tell the background is mostly a matte painting. What gives it away is that the candles in the foreground are flickering while the candles in the background aren't since they're painted.
Continuity mistake: When Joey drives up to The Boiler Room to find Doc, it alternates between not raining and downpouring, depending on the shot. (Ex. In the shots inside the car looking out, it's not raining. In the exterior shots of the car, it is.)
Audio problem: When Joey calls Doc and he asks her what channel she's watching, she says, "Uhh 12, I think." Her lip movements don't quite match the dialogue.
Continuity mistake: When Pinhead appears in the nightclub, there's a dramatic shot revealing him, and if you look, there's only one or two people to the left of the stairs. The scene then cuts away for about a second and a half, and when it cuts back, suddenly there's a whole crowd to the left of the stairs. Far too many to appear in such a short period of time.
Audio problem: During Joey's dream, as Elliot Spencer says, "Would you walk with me?" and they walk away from the camera as he begins explaining what's going on, their mouths aren't moving at all, and yet there's dialogue throughout the shot.
Continuity mistake: When Joey has the dream where she finds the radio in her closet, there are a few quick close-ups of her hand turning the radio dial. These close-ups are done with a hand double because you can see that the hand turning the dial has a clubbed thumb (sometimes known as a "short thumb" or "toe thumb"), whereas in other shots, she has a normal thumb.
Other mistake: After JP gets the pistons shoved through his head, there's an incredibly puzzling insert shot where we see him crumple to the floor. Suddenly, there's smoke coming off his head, his pants are different, his belt has disappeared, and the pistons on his head are randomly much shorter. It's almost like a snippet of an unfinished effects shot was randomly inserted into the scene.
Revealing mistake: When JP gets the two pistons shoved through his head and we see them "break through" his head, you can tell it's just two different takes of the same effect, since both come out ABOVE his ear, whereas when we see the final result, there's one coming out BELOW his ear. (The hairline on the fake prop head is also a little wonky.)
