Continuity mistake: At the beginning when both muggers are about to be jumped by Batman, one of them lights a cigarette and reassures his buddy that there's nothing to be afraid of. But while he's talking, the load of cash in his right hand vanishes between shots. (00:05:25)
Continuity mistake: When Nic is dangling helplessly above the back alley, Batman changes position on the building's ledge from one shot to the next (note the seam between his boots). (00:06:30)
Continuity mistake: When Knox takes the funny Batman sketch from his co-worker, his right hand jumps to a different part of the paper between frames. (00:13:10)
Continuity mistake: When Knox walks into Gotham Globe and gets mocked about his recent Batman article, a co-worker hands him a funny Batman drawing just to rub it in. But watch as a coffee cup on the worker's desk turns itself completely around between shots. (00:13:10)
Continuity mistake: In the scene where Vicki introduces herself to Knox at Gotham Globe, the newspaper she's reading changes between shots. (00:13:25)
Continuity mistake: At Gotham Globe when Vicki and Knox are talking about wildlife at the desk, Vicki's black shirt conceals her wristwatch between shots. (00:13:50)
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)
Continuity mistake: At the beginning of the movie when the police are standing outside of Axis Chemicals, Eckhardt has very distinct facial hair. In the next shot when they are inside the plant he is clean shaven. (00:23:05 - 00:24:10)
Continuity mistake: When Batman is gliding down to get Napier, there appears to be nothing attached to his belt, but when he is about to land, his rope gun has magically appeared on his belt. (00:26:40)
Continuity mistake: Towards the end of the gunfire exchange scene at Axis Chemicals - from the point at which Joker was pondering an escape on the catwalk until Batman turns around to see the shadow of a police officer closing in on him - notice how the exit bears an altogether different appearance between views. (00:27:35 - 00:29:40)
Continuity mistake: At Axis Chemicals, Jack's face is cut by broken glass and has blood gushing out of it. But in the next shot, Jack (probably the stunt double) does not have any blood on him as he goes over the edge of the rail. (00:29:00)
Continuity mistake: In the scene where Joker smashes a mirror on the surgical instrument table, a large fragment breaks off and hits the floor. That fragment somehow appears on the tabletop seconds later. (00:35:10)
Continuity mistake: In the alley, Bruce places two roses on a sidewalk and then walks away. But when Vicki gets to the roses, they have changed positions. (00:46:50)
Continuity mistake: When the mimes open fire on the gangsters, watch the police officers to the left and right above them on the top of the steps. In the overhead shot, right after they open fire, they disappear. (00:49:30)
Continuity mistake: Vicki has five photos of Bruce Wayne on a table. She picks one up, but when she is looking at it, through the back of the photo paper the snapshot looks different from the one she picked up. (00:52:30)
Continuity mistake: In Joker's hideout, Bob gives Joker the pictures he took and throws the folder that the pictures were in on the floor. But later in the shot above the room, the folder is no where to be found. (00:53:05 - 00:54:00)
Continuity mistake: In the scene where Joker is admiring a black and white photo of Vicki, watch as the crayons in his pink bucket on the table keep changing between shots. (00:53:05)
Revealing mistake: Harvey Dent and the mayor argue in Dent's office which has an unusual semicircular shape. In the next scene, Alfred uses the telephone in Wayne Manor, and you can see that it's the same room, just with different furniture and dressings. (00:56:10)
Continuity mistake: The background behind Bruce's TV set changes all by itself in the scene where he and Alfred are watching Joker's Smylex commercial. (00:56:55)
Continuity mistake: Harvey Dent is on the telephone while smoking a cigar that is partly ash. Two camera angles later he is smoking a brand new cigar with no visible ash. (00:58:25)
Answer: He was suspicious, but when she first entered the penthouse and Grissom said to leave their business meeting, he noticed the sexy facial exchange Alicia and Jack gave each other.