It is about sunset-time when 6 year-old Edward runs into his parent's room and hides in the closet. They must have talked hours, since when Edward is leaving the room, it is the dead of the night outside.
When Edward and Margaret are arguing in their room (a couple hours into the movie) the light switch on the wall next to the bathroom door goes back and forth from a blank plate to a switch.
When Edward has returned home from Europe and his son asks about his war service. While Edward is unpacking, at first he is taking out shoes and holding them when he notices his son has come in. Then as his son thanks him for the ship, he is taking out some clothes and holding them as he says "You're welcome." When his son says "good night" and exits, Edward is holding the shoes again.
When Edward first meets General Sullivan, the General's cane moves around between shots.
The scenes in war-time London show the characters walking outside at night under working street-lights, but London's streetlights were not turned on during war-time, in order to make it more difficult for German bombers to locate their targets.
Edward and Laura watch a newsreel filmed in Poland under German occupation; Several days later - enough time had elapsed for Edward to assist the FBI in exposing the members of "The American German Cultural Committee" - the couple go dancing and there they hear the announcement of Britain and France's war declaration on Germany. In reality, that event occurred on Sep. 3rd, 1939, merely 2 days after the invasion of Poland; Bear in mind that in WW-II era it took days for a newsreel to travel from the front to the cinemas.
When Edward is in Mironov's office, there's a picture of Mironov's family with two daughters. However, this contradicts his legend which states that he has 2 sons (and probably the true Mironov did). It is highly doubtful that he would do such a mistake and nobody would notice that inconsistency.
When Edward is relating his closely guard secret about when he was a child hiding in his fathers closet he says "there was his admirals jacket.", when actually it was a Captains jacket that was in the closet.
Just after the 45 minute mark, they play a recording of a jet engine. Only, this part of the movie is set in 1939 while commercial jets didn't exist before 1949.
After about half an hour of the movie when Edward is spying on
Dr. Fredericks at the gathering of the American German Cultural Committee, he searches through a handbag and digs up a membership roster. The title of the list is written both in English and German, but the German translation is atrocious, as if it had been done by translation software. It reads, "The [sic!] Amerikaner German [sic!] die Kulturelle Einrichtung Das Gremium". A reasonable translation, most likely used without article, would simply be "Amerikanisch-deutsches Kulturkomitee". It is highly unlikely that such an institution in which American scholars, not to mention Germans, played a role would fail to use a correct German translation.
The Finnish passport and driver's license include some questionable linguistic choices, which are here literally translated. The driver's license reads KANSAINVÄLINEN AJAMINEN PÄÄSTÄÄ ("international driving to allow"). It is from YHDISTETTY KANSA ("a people unified"), apparently a reference to Yhdistyneet Kansakunnat (Finnish for the United Nations). The license also reads: EI HYVIN PERUSTELTU KOTONA SUOMI ("not well justified at home Finland"). Also the first name is spelled wrong: it reads "Marti" which is not a Finnish name. Most likely it should read "Martti", a very common first name at the time. The passport includes the puzzling statement ESITYSTAITO LLA KANNATTAA ("presentation skill with is profitable").
Early in the film, in a scene set in April 1961, you can see a solid blue US Postal Service box on a street corner in Washington, D.C. In 1961 US postal boxes were painted red on top and blue below.
In 'Washington 1946' a Volkswagen is clearly visible. This car was first imported to the USA in 1949.
In the torture scene (1960), one of the songs the Russian spy sings, is "May There Always Be Sunshine". The song was performed for the first time in 1962.
The list in Dr. Fredericks' briefcase that Wilson copies was clearly made with a computer. Of course, these were not available at the time the movie takes place.
During Edward's stay in London during WW2 he is listening to a radio broadcast from a brown and cream colored Bakelite radio. The model, a Bush DAC10, wasn't introduced into the UK until 1950.
During a couple of scenes with Edward Wilson you can see a green screen reflection in his glasses.
Scenes set in wartime London include sounds of an air raid. The siren noise heard is for an American air raid siren, not a British one.
When Wilson is transferred to Berlin, the first original footage of the ruins of the city is subtitled "Soviet Sector, Berlin". In fact, the footage shows the area around the Kaiser Wilhelm Memorial Church, which was in the American Sector, and later on the center of West Berlin.
As a Russian, Mironov should have had his wedding band on his right hand.
At the start of the film, it states England has declared war on Germany. It should have said that Britain has declared war on Germany. There is more to Britain than England.
The last word in the phrase "We certify that this is" on the Gaim Swiss Bank check (right after Wilson asks Murack to reveal information about Philip Allen) is incorrectly spelled as "ia".
When the dollar bill serial number code is matched to the code sheet, the word "altar" on the sheet is misspelled "alter".
In the TELEX scene, the word "know" is incorrectly spelled "KONW".