Revealing mistake: When the reporter dies on air, her face is contorted into the Joker's face. When the camera is in closeup on her face, the "dead" woman's bottom lip moves.
Revealing mistake: In the film's ending shot, the sky can be seen to flutter as the camera pans up, revealing a backdrop.
Revealing mistake: When Batman fires rockets at the Joker, none come out, instead a sound effect is used which cuts to explosions on the road where Joker stands.
Audio problem: Bruce watches Commissioner Gordon on tape at his party. In the first part, the audio is laid wrong and their mouths don't match.
Revealing mistake: When Vicki is driving car Knox jumps on, you can see it's a stunt driver in the wide shots.
Continuity mistake: The clown balloon was swelling with the Smilex gas, but when Batman steals it and flies it and the other balloons away, it's back to normal shape.
Continuity mistake: When Knox and Vicki talk about Corto Maltese, she puts her left hand by her neck. Shot changes, and now both hands are on her neck. (00:13:51)
Factual error: It would take even a very strong acid a lot longer than a few seconds to eat through the thick metal bolts holding up the bell. (01:44:00)
Continuity mistake: Before and after his transformation, the Joker a.k.a. Jack Napier, has brown eyes, but in the flashback, he has blue eyes.
Continuity mistake: When the man is knocked out in the alley he changes positions between shots.
Suggested correction: The balloons were not filled with Smilex gas. The Smilex was in canisters that are visible underneath the balloons. The balloons themselves could have expended and contracted due to varying air pressure.
wizard_of_gore ★
Yes the canisters were on the underside. But if you look closely, when activated, the balloon began to swell, and holes appeared, releasing the gas.
Movie Nut