Continuity mistake: Alex's mother goes to make him a sandwich and squeezes jelly onto the bread. The shot comes back after both Alex and his mother talk before she goes out. The jelly has mysteriously been spread.
Continuity mistake: When Unger gets run over by his criminal partner, look at the driver side window. Making initial contact with the car, it is closed. For the close up shot, it's wide open, and when the car turns, it's only open a couple of inches.
Continuity mistake: The scenes where the bad guys get into Chicago are in daylight, but when they are "chasing" the taxi cab it is nighttime.
Continuity mistake: At one point, the mother gets an audible page. When she looks at the display to see the number, you can clearly see that the pager is set to "silent."
Continuity mistake: When Dupre knocks the washing basket off of the side, on top of the car, we see the basket land upside down, but in the next shot it is on its side.
Plot hole: The main criminal puts on the "butt inspection gloves" whilst searching the first house, but when Alex sees him through the telescope he pulls down the blinds and has black gloves on. Returning outside, they revert back. However, how does Alex know the criminal donned the rubber gloves (when he describes him to his mother), if he saw what we saw through the telescope - the black gloves?
Continuity mistake: At the end, when the parrot is going into the igloo, the igloo looks tiny from the outside, as if Alex would barely fit in there. But when the parrot goes into the igloo, the man can fit in there and there is so much more space in it.
Revealing mistake: When the criminals are supposed to be in a San Francisco airport, the scene was quite obviously filmed in Chicago's O'Hare airport. They then cleverly catch a flight to Chicago, and then come out at a different part of the O'Hare airport.
Visible crew/equipment: When Mrs. Hess' TV is off, if you look closely you can see the camera filming the shot and it's stand.
Continuity mistake: When one of the criminals confirms her position as "4th house, moving to the alley," the shot moves to Alex running from one window to the other, with nothing in his hands. He goes to push open the window and the shot changes again. Alex now has the car remote control as the window opens.
Visible crew/equipment: Alex fixes the TV to show a camera picture. The next scene when two of the criminals pull up in the car next to a mirror, a crew member is blatantly visible in the reflection, if you look closely on the left hand side.
Continuity mistake: Alex starts turning off Mrs. Hess' TV from the attic. The ornaments in front of the TV move between shots at least twice, in consecutive shots.
Factual error: In real life (there are a couple of scenes like this) snow doesn't fall from the sky at the intensity it was from clear skies.
Continuity mistake: In the scene where Stan is bouncing his basketball, Alex's grasshopper is crawling around on the floor. Notice the bug is a brown type of a color and then when Stan squishes the grasshopper it is green on the bottom of the basketball.
Continuity mistake: When Alex first takes out the bubble-squirting gun and threatens Olek Krupa's character with it, the muzzle looks like what one might see on a real gun. However, when we get a closeup of it after Alex shouts at Olek Krupa and chases him away, the muzzle has a gaping hole in it, because it's a different bubble-squirting gun.
Continuity mistake: Near the beginning, Beaupre and Co. follow a taxi driver to its station and we see it park. It pulls right up to a metal fence. However, when Jurnigen and Unger approach the taxi driver a moment later we can see in the background that the fence is a good distance away from the car.