Continuity mistake: Mr. Beaupre is talking to Alex in the garage, and Alex walks backwards away from him, he nearly touches the wooden shelf behind him. When it cuts to a wideshot Alex is now much further away from the shelf, and when it cuts to another closeup he once again walks back into the shelf.
Deliberate mistake: When one of the bad guys looks through the mail box slot, Alex sprays him in the eyes with black spray paint. Meaning the spray paint must have actually gone INTO his eyes, yet when he turns around, its only around the outer part of his eyes and no where in his eye balls.
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?
Factual error: During the remote control car chase the bad guys' minivan drives directly over it at one point. From the view of the toy car, you can see a driveshaft running down the centre of the undercarriage, which would be impossible on a front-wheel-drive vehicle like the Nissan Quest they're driving, which use half axles to drive the front wheels.
Other mistake: When Alex's mum calls the woman thief at the scene where the thieves are redirecting the phone calls, the screen shows Alex's mum dialling a number. The call is redirected to the thief's mobile, but notice that on the computer screen, "Interrupt" is spelled wrong, and instead is spelled "Interupt".