
Revealing mistake: When Luke is being fed to the Rancor, in Jabba the Hutt's dungeon, there are black outlines around the beast's legs, from the composite's blue screen special effect. This was edited out in the special edition rerelease.

Continuity mistake: When the real 'manager' comes outside to yell at "Mr. O'Donnell', you see the manager walk back into the club. If you look in the background of the next shot, you can see the manager walking through the door again. (00:13:25)

Continuity mistake: The final battle starts around dawn, and it's very dark when the bad guys arrive, but between shots it suddenly gets much brighter. (01:38:50)
Suggested correction: When you see the helicopter start flying in after Brixton asking them to bring it in, you can see the sun in the distance, so perhaps some time passed by.
But the weapons are only disabled for 6 minutes and the 6 minutes end when they're hooked up to the chopper, which is way later.

Factual error: When Philby and Alexander are talking about Albert Einstein, Alexander mentions that Einstein is a patent clerk. The beginning of this movie takes place in the year 1899. Einstein was still in school and didn't become a patent clerk until 1902.

Continuity mistake: The case files which Agent Cowles brought to the kitchen and put on the countertop disappear shortly after being placed there. (00:08:30 - 00:09:10)

Continuity mistake: In the shot of the alien's tail wrapping around the back of Lambert's legs right before it kills her, the floor is different to what it was before, there is water suddenly falling from the ceiling when there wasn't before and her trousers have changed from white to blue. This is because that shot was originally intended to be used when Brett was killed.

Character mistake: The commentator says "avalanche of power shots by Ivan Drago." Viktor is the one in the ring. Ivan is the father. If you have the subtitles turned on, it even says Viktor in the subtitles instead of the spoken name, Ivan. (00:55:45)

Other mistake: In the beginning of the song about Augustus Gloop, computer generated Oompa Loompas can be seen running through the Chocolate Room, preparing to sing their song. In the DVD release, some Oompa Loompas can be seen running to places that no real person could possibly stand on. This mistake was later corrected in the Blu-Ray release.

Plot hole: Suzie pulls out some of her teeth with a pair of heavy pliers. This would leave conspicuous tool marks on the teeth that would be visible to the naked eye, let alone under forensic examination. The conclusion would be that Suzie is missing, not dead, and the whole plot would unravel from there.

Revealing mistake: Near the end when Ace gets into his Cadillac, in the first shot facing the front of the car, there is a protective glass in front of Ace (the same width as the windshield) with the dashboard in between that glass and the windshield. Note the vertical edge of the glass is visible at the right side, and the rearview mirror's sticker on the windshield casts a shadow onto the second glass. During the stunt, the flames on the dashboard are between the glass shield and the windshield, keeping the actor safe from harm. (02:46:05)

Continuity mistake: He cuts a hole in her pants for insemination. When in the car moments before fighting the dog there is no hole.

Continuity mistake: When they steal the truck at the mall they have to hot wire it to make it start. Later at the San Andreas fault scene where the road ends, in the same truck, he turns the truck off with the key.

Continuity mistake: When Viper confronts Shingen, she removes her left glove twice.

Continuity mistake: Dick Jones brags (admits?) to Robocop, "I had to kill Bob Morton because he made a mistake. Now, it's time to erase that mistake" while Robocop is crouched on the ground, not only looking away from him from across the room, but also Robocop's eyes are in a vertical position. In the playback, Jones is facing the camera as though it were videotaped or filmed in a studio. (01:10:50 - 01:35:10)

Revealing mistake: At the beginning of the scene near the end of the movie with Lucius Malfoy fuming at Dumbledore in his office, Malfoy's hair is fanned back behind his shoulders. The lighting in the room illuminates the back of his neck, where you can see his real, short brown hair. (02:22:05)

Continuity mistake: When Annie and Laurie leave the hardware store to go to their babysitting jobs it is broad daylight. When they reach the houses apparently just a few blocks away, it is already dark.

Factual error: Under US law neither Peter Lowenstein nor Oscar Grace would be allowed any level of participation in the investigation, arrest and prosecution of Ned Racine. Both have a highly visible social relationship with him, which disqualifies them from having anything to do with a criminal case against him. In fact as soon as he became a suspect in Edmund Walker's murder they would both be officially 'warned off' - told not to contact him again for any reason.

Continuity mistake: At the beginning when Indy is talking to Spalko, his hands keep alternating from being in his pockets to just resting at his sides between shots.

Plot hole: Patrick Redfern needs someone to be in the boat with him to corroborate his and his wife's deception and be his alibi. That is whole point of his wife lying on beach - he gets this when taking Myra for a ride - but it was portrayed as a random ride she got, he did not intend or plan giving her a ride, he did not see her loitering near the boat, or even in view of him untying the boat. Even if that was intention in the story for him to be seen ready to cast off, the movie viewers did not see her viewing him, only her appearing just before he was set to cast off. Without someone with him the whole deception would not work, he would have no alibi, he could have killed Arlena unseen.

Factual error: The interior shots of the Gemini and Apollo Spacecraft show worn and dirty panels, knobs, switches and circuit breakers. The movie most likely used some original cockpit trainers, but in reality the astronauts were flying brand new spacecraft that were spotless.
Suggested correction: All spacecraft are extensively checked out by technicians before mating to the launch vehicle. Launch rehearsals are done over and over again by both prime and backup crews in the real vehicle in the weeks leading up to launch. Gus Grissom, Ed White, and Roger Chaffee lost their lives in a fire aboard Apollo 1 during one such dress rehearsal. The switches and panels get worn from this use and activity. Crews also make minor modifications to their specific craft to suit the mission and tastes.
Suggested correction: This was not a "mistake". The outlines showing around the beast's leg were due to the limited CGI technology at the time the film was made. With advances in special effects in the following decades, the filmmakers were able to enhance the CGI quality in later releases.
raywest ★
But it is a mistake to show that the Rancor is not real, and the outlines show that. It's certainly not intentional.
lionhead
Not sure what you mean that the rancor is not real. Of course it's not real. The issue is, at that time, it was not technically possible to show the beastie without the lines showing. I classify a mistake as something that was not intentional. In this case, it was, due to the limitations of CGI in the 1980s.
raywest ★