Continuity mistake: In the junkyard, after Ludo pulls Sarah out of the garbage room, Sir Didymus says "M'lady look, we're almost there...." and then there is a shot of the gates to the Goblin City. The junk which sits around the gates to the Goblin City is piled rather low. However when Sarah, Ludo and Sir Didymus arrive at the gates, the junk to the right hand side of the gates is now piled up much, much higher. (01:11:30)
Continuity mistake: When Sarah is hanging on the branch over the bog, Ludo calls a rock and the rock rolls into the bog, and is pretty round, with no large flat areas on it. However when it's floating in the bog, Sarah jumps onto it and the rock now has a very large flat area. (00:58:45)
Visible crew/equipment: In the Goblin city, Ludo calls the rocks and the rocks emerge. There is then a shot of a soldier on his stead, wearing orange armour, tumbling over as he gets hit by a rock. As he falls, the wires holding him are blatantly visible. (01:20:50)
Continuity mistake: As Sir Didymus bangs the large grey brick holding the bridge up and says "Have no fear sweet maiden...", the large brick then suddenly falls. Between shots the amount of green fungus and moss covering the grey brick increases. (00:58:10)
Continuity mistake: As Hoggle and Sarah fall out the end of the chute that leads to the Bog of Eternal Stench, look closer and you can see that Sarah falls through the end of the chute twice. (00:52:45)
Continuity mistake: Sarah is rescued from her fake house and head towards the gates to the Goblin City. Hoggle is seen poking his head out in the wide shot and then a close-up. The things around Hoggle change in the two shots. (01:14:25)
Continuity mistake: Ludo holds Sir Didymus up by his staff and promptly drops him on the ground. He gets up, whacks Ludo in the knee with his staff and then his plastic staff bends and folds over as it hits the knee. Yet in the following shots his staff is creaseless and straight again. (00:58:10)
Continuity mistake: After Sarah runs up the stairs and shouts, "I can't do anything right, can I?" in the next two close-ups of her stepmother, the foyer table stands on an area rug with multi floral at the edge, inner red floral and a center floral medallion. As the camera pans out in the next shot, the table stands on the medallion, whereas in the previous close-ups it stood farther over, on the red. (00:05:35)
Continuity mistake: The twin doors in the bedroom fly open, and as a result the curtains are opened and pulled behind each of the doors as the owl flies through. However in the close-up of the owl attacking Sarah the curtains are visible and they are now blowing in front of the open doorway. Then as Jareth's shadow is seen on the rug, it's clear that the curtains are pulled apart by their shadow, which is also the case in the next shot of Jareth standing in the doorway with the curtains indeed pulled behind the doors. (00:11:45)
Audio problem: Having reached her house after running home in the rain, Sarah's stepmother stands on the porch and we hear her say, "Oh, really," but her mouth does not move at all. (00:04:45)
Continuity mistake: When Sarah first meets the Goblin King, she has on Camel colored semi-formal flat shoes, but when she starts the labyrinth, her shoes have changed to brown suede loafers. She didn't change her shoes beforehand.
Continuity mistake: In Sarah's fathers bedroom, the green chair that sits by the back doors changes position during the scenes, and the cushion and soft toy that sit on it often change their position as well. (00:08:05)
Continuity mistake: When Sarah runs to the side of the 'bubble' and smashes the glass with a chair, you can see that the table and the chair that she uses aren't reflected in the glass as she runs up to it. (01:06:30)
Audio problem: In his throne room, Jareth starts to sing, "Dance, magic, dance..." In the overhead shot when they sing the words, "Put that magic spell on me," he kicks the little guy up, then in the next front shot when he sings the second line, "Jump, magic, jump," and just before and during which he throws Toby in the air, in all these shots either his lips do not reflect the words heard or his lips move and no sound is heard. (00:23:55)
Continuity mistake: When Sarah is at the park reciting the Labyrinth play, she has stud earrings in each ear. When she arrives home and then argues with her mum, they have gone. (00:03:10 - 00:05:25)
Revealing mistake: Back in her room Sarah puts things away in her vanity drawer, including her music box. The diameter of the music box is greater than the height of the sides of the drawer, which would prevent the drawer from closing properly. On the white front of the vanity table above that drawer, the top lip is cut away to allow for the important shot of Sarah closing the drawer. (00:34:40)
Continuity mistake: Sarah goes to pick up the fairy that dropped right by the wall. But in the next shot, you see Sarah stand up with the fairy in her hands, and she is now standing quite a way from the wall. (00:14:55)
Continuity mistake: When Sarah first enters the labyrinth, and is running down the passage, the branches, bits of log and wood etc., change, disappear and reappear between different angled shots as she runs. (00:17:45)
Continuity mistake: When Jareth throws the snake at Sarah, from a back shot the snake goes over her shoulders and crosses over by her neck, but in the next front shot the snake is only in front of Sarah and isn't over her shoulders anymore. (00:13:00)
Revealing mistake: During the 'Dance Magic Dance'-sequence in Jareth's throne room, David Bowie throws up a baby dummy (it's near the end of the song). (00:26:00)
Answer: To add to that, the other door was supposed to lead her to certain death, and technically the oubliette wasn't exactly certain death.