Revealing mistake: When the Angels are fighting the "Creepy Thin Man," right before Drew Barrymore lifts up Lucy Liu to spin her around and kick the thin man, to get Lucy's attention, Drew hollers out "Lucy!" even though Lucy Liu's character's name is "Alex." (00:26:20 - 00:27:25)
Revealing mistake: In the swimming pool scene, when David is sitting at the bottom of the pool, you can clearly see a scab on one of his knees. (00:43:00)
Revealing mistake: How on Earth can Selby get those skin tight T-shirts over that huge cast on her arm? They cannot possibly stretch any more than they already are - look at the scene where she and Eileen are checking the mail. There is no way that sleeve would fit over the cast without ripping! It is well beyond the capacity of that tight T-shirt to stretch to that extent! Obviously Christina Ricci had the cast fitted after she was in costume.
Revealing mistake: When the leading hitman jumps from the balcony you see him land on a rubber mat.
Revealing mistake: When Austin enters the bathroom at the casino, keep your eyes on the door during the scene - it opens by itself before closing. (00:31:10)
Revealing mistake: As Kevin is flying off the front porch on the toboggan, you can see the small wheels mounted on the bottom of the sled to aid in its "jump". (00:25:30)
Revealing mistake: When they get back from Bunyans and the garbage is on the floor, Chet runs to the bathroom. The family and Roman follow him, you see Dan do a 3 count for everyone to run back In screaming, the blocking of that shot included a gap that you could see them off camera right.
Revealing mistake: When Henry hits one of the corrupt cops in the head with an otoscope it bends off his head like rubber.
Revealing mistake: When Tommy Ross gets killed and Carrie looks at his supposedly lifeless body if you look closely you will notice he blinks revealing that he is actually alive.
Revealing mistake: When Carl is being dragged away by the demons, you can see the cable line that he's attached to. May be fixed on DVD.
Revealing mistake: In one shot when the boat is pulling away from the waterfall, you can clearly see that the shot is the same one they used earlier in the movie. The water from the waterfall now is going up the cliff! They have just put it in reverse.
Revealing mistake: When Louis gives Gage the lethal injection, because the syringe is transparent you can actually see the prop needle retract in and out of the syringe as he supposedly injects Gage.
Revealing mistake: When Dracula flies into the room to stop his brides from devouring Jonathan, the board carrying him is visible. (00:34:10)
Revealing mistake: During the bedroom scene with Felicity and Fat Bastard you can clearly see the air hose that fills his suit when he rolls over in the bed. (00:49:10)
Revealing mistake: When Lara Croft goes into the water near the end to try to save her male rival, Alex West, after he is stabbed and ground between the gears, when Lara stands up, you can see the make-up coming off her arm that covers Angelina Jolie's "Billy Bob" tattoo.
Revealing mistake: There are supposed to be two dead young Asian males sitting in the back of the car, but in this shot, it is so obvious that there are two dead 'dummies' riding in the back. Also, in the crash, a few seconds later, very blatant dummy heads are flying everywhere. (00:40:40)
Revealing mistake: When Anna and Hans are dancing in front of the lighthouse, we don't see the shadow of the railing or the ground they're standing on.
Revealing mistake: When The Mask is dancing with Tina and he turns her into a human tornado while spinning her around, none of the onlookers in the crowd show the slightest bit of amazement at the impossible feat that just occurred in front of them, indicating that the extras were not directed to react to the special effects.
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.
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.
But it is a mistake to show that the Rancor is not real, and the outlines show that. It's certainly not intentional.
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.
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)