Revealing mistake: In the opening sequence, when the robbers are on the zip line, two Chicago Police squad cars (white cars with blue markings), not Gotham PD (blue with white markings) can be seen blocking off Van Buren Street for the filming. (00:01:05)
Revealing mistake: When Harvey Dent turns on the Bat Signal, Lt. Gordon comes out of the rooftop stairwell. As the door opens you can see that there is no back to the stairwell enclosure, and you can see the city. (00:25:15)
Revealing mistake: As Harvey Dent is tied up in the warehouse with the explosive barrels talking to Rachel, if you look in the lower right hand corner of the screen, a green blanket on the floor moves up slightly as Harvey tries to get out of his restraints. It's too far away for Harvey to touch. A person's fingers or hand is also momentarily visible in the previous establishing shot when Dent is regaining consciousness.
Revealing mistake: When Batman's cycle flips the truck that the Joker is driving during the scene in which The Joker is attempting to kidnap Harvey Dent, the viewer can see the geyser of compressed air shooting from the underside of the 18-wheeler's trailer, which is commonly used to flip vehicles for movie stunts.
Revealing mistake: In the opening scene, the Joker is picked up by some of the other crew members. While he is sitting in the SUV, he inserts a magazine into his Glock pistol and pulls back the slide to chamber a round. However, when he does, the slide locks back, indicating that the magazine is empty. (00:02:05)
Revealing mistake: When the Joker first meets the mobsters you can see the reflection of the green screen on the table instead of the TV image. (00:23:30)
Revealing mistake: During the interrogation scene, when Gordon first enters, as he begins to close the door if you look in the glass reflection on Gordon's left (screen right), you can see the door open again slightly after he shuts it. In the next shot, its completely shut and locked.
Revealing mistake: In the scene where Batman is taking down the SWAT members to prevent them from harming the wrong people, one of the SWAT guys is lying on the ground and attempts to stand up. The clip for his gun contacts the ground and flexes like a rubber stunt gun would, not a real clip and gun.
Revealing mistake: When The Joker destroys the hospital the windows on the second and third story don't reflect anything. This is because the day before shooting at the abandoned building vandals broke in and destroyed the windows, meaning they needed to be replaced by CGI. Confirmed in the "Making of". (01:52:35)
Revealing mistake: As the SWAT guy preps a charge, the false section of the wall is outlined.
Revealing mistake: When the Joker shoots the bank manager and he stumbles to the floor, you can make out the shape of knee pads under his suit. (00:04:40)
Revealing mistake: Gotham General blows up but it appears to be an abandoned building. The shot pulls out after the Joker gets into the bus and you can see sky right through the building.
Revealing mistake: In the scene after Batman thwarts the Joker's attempt to kidnap Harvey Dent by making the lorry the Joker is driving crash, the Joker crawls out of the lorry, picks up a gun and starts firing. In the background on the right alongside the Joker is a shop with the sign 'Sweet Home Chicago', where the scene was filmed - it should be Gotham. (01:18:35)
Revealing mistake: The Lamborghini Murcielago that Bruce Wayne drives changes from a real Lambo to a fake one - in the long shot (down an alleyway) showing the Lambo at the end of the street, It's obvious the wheel base is too short and the ride height is too high. It makes no sense why they would use the fake Lambo in this shot, as the car doesn't get damaged until later in the film. (01:46:00 - 01:51:00)
Revealing mistake: In the chase scene, the police helicopter appears to have NYPD markings instead of Gotham Police. (01:12:00)
Answer: It's habit, and a sensible one at that. When he's in the mask, when he's being Batman, he uses the voice, even if the person he's with knows who he is. If he drops back to his normal voice with some people, it sets the precedent for using it while wearing the cowl, which means that he's more likely to slip up and use it around people who don't know, potentially revealing his true identity. If he sticks rigidly to using the voice when kitted up as Batman, regardless of situation, it minimises that possibility.
Tailkinker ★