Continuity mistake: When Ace is trying to work out what Einhorn and Finkle have to do with each other, his dog sits on a photo of Finkle and its hair does not cover the face, the shot moves to Ace and then back to the dog and now its hair is covering the face of the photo without even moving. (01:03:30)
Continuity mistake: When Ace is sneaking into Ronald Camp's Private Aquarium, he begins to look around and open some doors. If you look at the colour of the wall it is red. When he opens the door to the giant tank, the wall outside the door (which should be red) is now white. The door also reverses - the handle goes from Ace's left to Ace's right. (00:28:50)
Continuity mistake: When Ace is in the asylum, he is trying to hide in a little cardboard box from an employee of the building, so he crams himself into a box and when the man leaves he breaks out of it. He ends up completely squishing the box underneath him. When the camera comes in for the close up shot, the farthest side of the box from the viewer is now undamaged. (01:00:30)
Continuity mistake: When Mr. Shikadance looks around Ace's apartment the dog door on the fridge is one piece. Later, when the penguins come out it has five strips making it easier for the penguins. The rug moves closer to the fridge too. (00:09:35)
Deliberate mistake: In the scene in which Ace is in the asylum, he breaks into a storage closet to view Finkle's belongings that were left behind when he escaped. At first the doorframe is such that the door closes against about an inch of wood, meaning the lock would be behind this wood, so Ace couldn't pry it open. In the closeup, the door's flush against the frame so Ace can use the sign to get between the door and the frame. In the wide shot it's back to how it was. (00:58:55)
Continuity mistake: At the end of the mission impossible music, where Ace is sneaking into the billionaire's private Aquarium, there is a plant in the hallway shown from outside of the building when Ace swings opens the door. When he slams the door shut and is inside the building no plant is there. (00:28:35)
Continuity mistake: When Ace is at the mental hospital, inside the storage room, he steps on a piece of bubble wrap. He picks it up, looks at it and throws it to the side. Throughout the scene the bubble wrap moves away from the shelves then close to them again. (01:00:15)
Continuity mistake: In the opening scene, someone is crawling through the shattered rear windshield of Ace's car while it is in motion. They show a shot from inside the car and the guy has about half of his body in the car. When they show an outside shot, his hands are barely inside the car. Then, in the next inside shot, half of his body is still in the car. (00:04:50)
Continuity mistake: In the scene where Ace is trying to find a connection between Finkle and Einhorn, there is a shot of his monkey walking along a mantelpiece to the right hand end. There are 2 photos in frames on the mantelpiece, one of which is right up against a heavy book that is flat on the mantelpiece. In the next shot, zoomed in on the monkey jumping on the book there is no sign of the photo that should be touching the book. (01:02:45)
Revealing mistake: When Ace's car flips over you can see the left wheel is elevated over the bush. If you look closely there is a wooden plank there to help the car lift itself over the bush. The other mistake in the shot is that there is no conceivable way the bush would have flipped the car. Unless there was something very solid in front of the bush, the car would have just gone right through the bush. (00:52:05)
Continuity mistake: At the beginning of the film when Ace is kicking the box down the apartment's hallway and he says, 'We're going downtown.', before he says that the box is up against the wall in a normal position, after the close up of Ace saying this, the box has moved to a different position. (00:01:50)
Continuity mistake: When we first see Finkle's room, it's an inside shot and it's completely dark. But when we see the rest of the room, there is a "shrine" to Marino, with candles already lit. (00:49:00)
Revealing mistake: When the bad guys are shooting at Ace, he catches a bullet in his teeth. However, he goes from his lips being tightly shut to suddenly having the bullet in his teeth, obviously hiding the bullet in his mouth. (00:52:00)
Chosen answer: That scene was cut originally by the director Tom Shadyack because the scene did not support the story and thought it slowed the film down. (And the scene was cut from the US version as well.) It was added back later in TV versions of the film. Fan enjoyed the scene so much they asked it be put back in the film version. I know the DVD has it because I own it. It's hilarious!