Other mistake: When Ace rescues the dog and replaces it with a toy dog, the toy dog is in an impossible position. Ace had to place it there when the door was still open, but if the door was closed after that the man would have knocked it over. (00:03:25)
Revealing mistake: When Ace and Melissa are in bed together having sex if you look close enough you can see that she is wearing underwear. (00:45:35)
Audio problem: At the beginning, when they steal the dolphin, you hear the peel-out sound effect as if the truck was on a paved road, but they were on grass. (00:07:15)
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)
Revealing mistake: At the end of the movie, when Ace is at the stadium and he attacks the mascot, his name is called and he looks up to smile and wave. He is surrounded by players from the Miami dolphins, but if you look through the crowd of players you can see the stadium seats are empty. (01:18:25)
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)
Continuity mistake: In the beginning when Ace is "delivering" the package he walks into an elevator and the doors quickly close on the box, but when nothing is blocking the doors, they close much slower than the first time. (00:01:25)
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)
Revealing mistake: At the very beginning, when the guy is hanging on to Ace's car and Ace drives off, there is a shot of the dog biting the guy, but if you look closely, you'll see that the dog doesn't even open its mouth. It just sort of brushes his hand. (00:04:55)
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: In the scene where Ace just gets out of the empty dolphin tank at the football field, Roger Pedacter (Football coach) is trying to stave off the media. Take a look at the sweat stain on his shirt and see how it changes sizes. (00:16:40)
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)
Audio problem: Right after the "Mission Impossible" theme when he gets into the shark tank room, he slams the door, but you hear the door slam before it actually slams all the way shut.
Character mistake: In the scene at Roger Podacter's condo building, you hear the reporter mention that he allegedly leaped to his death from his own 20th story balcony. As the camera pans down, you can see the flashlights and people up on his balcony doing the investigation. This is the 2nd from the top floor. If you count the floors as the camera moves down, there are more than 20 floors to this building. The number is actually closer to 30. Even though it is difficult to get an exact count of the floors, it is still possible to tell with 100% certainty that his unit was on a floor higher than 20.
Revealing mistake: In the scene where Ace visits Woodstock's secret office at the music club, pay attention to the computer screen when Ace asks him to tap into the aquatic supply stores to track the sale of equipment for transporting a dolphin. Woodstock says, "All right, we got marine winch, sling, feeder fish, 20,000 gallon tank..." As he is saying this, the computer screen shows a bunch of non-related items (plates, cups, concrete, stone) with crazy numbers that don't make sense. It was as if someone was in a hurry to create a fake spreadsheet to use in the movie that they just pounded on the keyboard and a bunch of numbers came out. If you look through all of the items, it's actually funny how they are so varied (dog food, speakers, sneakers, soup, chairs) and have nothing to do with the story. Many of the items also repeat with different sets of numbers.
Other mistake: When Ace and Dan Marino pass in their car, on their way to the Superbowl, the stadium in the background is the one holding the special event, yet there's no car in the parking lot.
Continuity mistake: In the apartment crime scene, Sean Young says "we'll let you know if we find a tic", and the large grey-haired cop on her left chuckles, arms by his side. We then cut to a close-up of him with his hands on his hips, pushing his jacket to the sides, then back to the original shot with his hands by his sides again. The close-up itself is a bit weird - Sean Young should be right in front of him, but isn't visible. They must have used a later shot, because after about a minute, when everyone's moved around a lot, we see him back in exactly that position, only now the people visible fit the scenario better. (00:38:10)
Audio problem: In the scene where Ace gets attacked by Ronald Camp's shark, while he is being tossed about in the tank you can hear a crew member shout, "Great.". This may only be on the VHS version.
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!