Continuity mistake: When the FBI are rushing to reach Alex, as the snowploughs sweep the spy's car aside the front plough sweeps to the left. Further down the street the front plough sweeps to the right.
Continuity mistake: In the very first shot of the Mom, she carries in a load of boxes. Two green ones are included, one with writing above the other. When she unstacks them, the shot pans out a little bit, and the boxes are positioned differently.
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: Alex's Dad hangs up the steamer in the attic, when Alex informs him that his taxi arrives. The metal holder the steamer hangs on changes position with every shot.
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." (00:29:20)
Continuity mistake: Alex puts the present down to take off his hat and scarf, by the front door. Between shots the present moves a few inches closer to the bag next to it. (00:11:00)
Continuity mistake: In the scene where Alex's mum is about to leave his room after applying lotion to his chest. Alex's hair is slightly scruffy - when the shot comes back to him after being on the mum his hair is combed and neat.
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.
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. (00:16:35)
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.
Continuity mistake: The main bad guy has Alex cornered in Mrs. Hess' garage. Look at the clear plastic cup behind Alex. One shot the cup is upright, the next it is on its side.