Goofs

When Art gets out of the ambulance and climbs the fence with Simon he goes over first and then lifts Simon over. Art holds Simon tightly as he crawls on the ground between the fence and a train track. Art pauses and peers down the highway having never released Simon. Then, one second later, Simon is a hundred yards down the track, behind Art, walking headlong into an oncoming train. It's impossible in the transpired time for Simon to have covered the distance at his meandering pace.

Jenny is shot in the back and collapses forward, landing face-down. Later she is shown lying on her side.

Waste bin in Leo's flat is under the desk when Leo throws the carbon paper away. Yet when Emily finds bin, it is part way out from underneath desk.

As Simon removed the cap from the marker before starting a puzzle, he set the cap down. The next few shots, the cap was attached to the marker as he was working on that puzzle. When he finished the puzzle, the cap is back on the table and he picked it up from the table.

When Leo calls Dean to his office to hear the recording of Simon's call it is played back out of order. The original was Leo asking, "Who is this?" and Simon responds, "You are a stranger." Then Leo asks where he got the number from and Simon gives the puzzle number and Leo asks, "What did you say?" then you hear Simon's mother telling him to hang up the phone. The recording is played back with Leo asking "What did you say?" Then Simon's mother telling him to hang up the phone.

Kudrow insists repeatedly that the autistic boy's breaking the code puts agents in the field in danger. However, early in the movie, the two computer nerds establish the code is not yet in use. They placed it in the puzzle magazine as part of testing before implementation.

However, Kudrow's point was that the supposedly unbreakable code was now useless, and current encryption was still vulnerable to breaking.

In the ambulance, they skip the green card in Simon's collection, which is why they appear to be in a different order on the train.

When Art Jeffries is driving the stolen ambulance on the freeway, the assassin takes two shots at Art and Simon using a silenced pistol. The second shot shatters the ambulance windshield; this is not possible since all windshields are laminated glass. in reality, there would only be a small hole in the windshield, maybe the windshield would be cracked, but definitely not shattered.

When Art is driving the ambulance, the view is from the front, with the word "Ambulance" clearly readable. However, the word is always printed in reverse on the front of an ambulance, so that it can be read by drivers looking in their rear-view mirror. The film has not been flipped, because it's clear that Art is sitting in the ordinary driver's seat.

In the subway tunnel, part of the supposedly stone wall moves when Jeffries brushes up against it.

When Emily walks into her boyfriend's apartment, her lips stop moving for a brief moment but she doesn't stop talking.

When Art breaks the door to Simon's house, he closes it and the door clicks even though Art broke it.

The sound effect of a tooting locomotive air horn is incorrect for a Chicago CTA "L". CTA trains make a whistle-like bleeping sound.

On the bank's security camera video tape of Art and Dean crossing the street, knee pads are visible beneath Dean's pants in preparation for his fall.

When Simon calls the puzzle line the second time, Art takes the phone and speaks to Dean but does not say his name, only that he is FBI. When Art meets Dean the following day Dean knows Art's name is Agent Jeffries.

When the hit-man shoots Simons parents, he shoots his mum first. A hit-man would take out the man first, being stronger and having a better chance of disabling the hit-man.