Crew or equipment visible: When Kate Burroughs and Eric O'Neill are talking near the end of the movie inside Hanssen's office. You can see a crew member making slight movements in a picture frame's reflection on the bookshelf.
Anachronisms: In a number of scenes, computers were displayed clearly showing Microsoft 'Windows XP' screens. Windows XP did not appear until October 25, 2001, well after the time the movie was set.
Anachronisms: Post 2001/2002 cars are shown (e.g. 2003 or newer Honda Accord seen near beginning of movie).
Incorrectly regarded as goofs: In the long shot of the scene of a traffic jam on Memorial Bridge, no-one is in the driver's seat of any of the cars. This is probably because those cars are parked, not stuck in traffic. On that part of Rock Creek Pkwy in DC, there is parking on both sides of the street. There is only one lane of traffic in each direction, with room for cars on both curbs for parallel parking.
Errors in geography: As Hanssen and O'Neill are driving to an office in Virginia, one of the FBI agents reports over the phone that they are traveling on Wilson Boulevard, when in actuality they are driving on Arlington Boulevard/Route 50.
Continuity: Eric looks at Robert's computer at Roberts’s house. Eric then slides the mouse back into place without turning off the computer, when he realizes that Robert is on his way in from the back yard. When he slides the mouse the computer monitor shows that the computer is turned off. The mouse would have re-awakened the computer if it had been on standby.
Continuity: The Dell laptop and LCD monitor that Robert has in his office, when he shows Eric a movie clip with Catherine Zeta-Jones, was manufactured after 2001. While driving on Wilson Boulevard, the license plate on the back of the black SUV Eric is driving is a Virginia plate. In the traffic jam in the next scene, the license plate on the front of the SUV is clearly a Washington DC plate.
Factual errors: When Hanssen is instructing Garces on what's required for the new system, he requests an "OC-48 (connection) with a data rate of 2.488megabits (per second)". An OC-48 connection, in-fact, has capacity for 2488 megabits per second. In addition, anybody in the IT field would never refer to it this way: they would state something along the lines of, "Two and a half gigabits per second" not "Two point four eight eight"
Errors in geography: In the night street scene in front of Eric's apartment, set in DC, there is a Canadian "Do Not Enter" sign clearly visible in several shots.
Continuity: When Kate is explaining the details of his assignment, she has the pager sitting on the table. When she tells him about it, she is holding it. The camera switches to Eric's perspective and she brings her hands up from under the table to slide the pager over to him.
Errors in geography: The producers thank "Fairway County, VA" for the use of the park where the drop is made. The park is in Fairfax County, VA.
Continuity: When Hanson and O'Neill are driving on the highway, the Kennedy Center For The Performing Arts appears almost directly to the left of O'Neill. The screen flashes to Hanson, then when it goes back to O'Neill, the Kennedy Center is farther away, as if they are just now driving toward it.
Anachronisms: The mail with the video tape is sent to 5311 Bonn, Germany. The German zip code system was changed from 4 to 5 characters in 1993. Additionally the street mentioned on the envelope, Auberg Strasse 24, does not exist in Bonn.
Errors made by characters (possibly deliberate errors by the filmmakers): When Robert Hanssen mention swapping out the "WAN" for "ATM" he mispronounces WAN similar to "Jaun" when it should rhyme with MAN.
Continuity: When the agents are disassembling Hanssen's Taurus, they are seen removing an alloy wheel from the driver's side front. However, the vehicle is a Taurus GL which had steel wheels with plastic covers seen in the rest of the film.
Factual errors: When depicting the two Russian KGB officers who are given up by Hanssen, the officers are shown getting out of a black Mercedes flying a Russian flag and bearing a red license plate beginning with 036. In fact, red license plates in Russia denote foreign diplomats and 036 in particular denotes Iran. The correct license place color would have been black, which denotes a military vehicle. The license plate's last two digits, 77, were correct in that they denoted the geographic area of Moscow, which is where Linney's character said the Russian officers were brought.
Factual errors: The two Soviet KGB Agents are shown getting out of a car with a Russian flag on the front. The Russian flag was not adopted until 1991. The agents were executed under the old Soviet Union.
Factual errors: When Eric O'Neill removes Robert Hanssen's Palm Pilot from his briefcase you can clearly see the Palm Pilot Model is a Palm III, which doesn’t use an SD memory chip, which is lying next to it. This Palm has a 8 meg of internal memory only -- no External memory card.
Anachronisms: Signs on one of the Washington, D.C., metro stations used in the movie read "Archives-Navy Memorial-Penn Quarter," but the words "Penn Quarter" were not added to the station name until January 2004, three years after the movie takes place.
Errors in geography: The metro station labeled as "Archives-Navy Memorial-Penn Quarter" that Kate exits when meeting with Eric is actually the Federal Triangle metro stop. The adjacent Post Office Pavilion is visible in the background.
Factual errors: Security. Typical government safes containing classified information have the combination lock on the top drawer (not the second drawer down). Moreover, that combo lock, when unlocked, unlocks the top drawer AND all of the drawers below it. Thus, in one of the initial scenes of the movie, it is absurd to show a security safe with some drawers marked "OPEN" and others marked "CLOSED." The standard procedure is to open the safe, then place the "OPEN" sign on the top drawer. Anyone entering the office understands that that means the entire four or five drawers in that safe are NOT secured.
Anachronisms: Seen in the film is a Blue Mercedes-Benz ML Sport Utility Vehicle, not built until Spring 2005.
Revealing mistakes: About 30 minutes into the movie, when Eric looks at the Internet History on Hanssen's computer, one of the URLs displayed uses incorrect syntax: "www.church/democrats/clinton.com". The slash character is invalid in a top level domain name (www.imdb.com for example).