Factual error: When Ana is talking to Christian on her cell at the bar and he hangs up on her, you hear a dial tone. A dial tone wouldn't be heard once a cellular call disconnects. Dial tones are only heard on land line phones. Both were on their cells.
Factual error: The year is 1952. In an exterior scene, Saoirse Ronan is seen on a street in Brooklyn. In the far background, a red "WALK/DON'T WALK" sign is flashing. This type of sign was only introduced across NY in the late 50s.
Factual error: There seem to be modern "Walk" and "Don't Walk" signs at each intersection. This film is supposed to take place in 1952. Also it is mentioned there are "Stereophonic" consoles in the motel rooms. Probably would not find those until at best the late 50s.
Factual error: Ann plays an organ in a church with no electricity. And no, there was no manual bellows to make it work; the movie makers simply didn't know the difference between the operation of an organ versus that of a piano.
Factual error: Numerous military personnel salute while bare-headed in the film. British military personnel only ever salute while wearing headdress.
Factual error: During the opening credits a newspaper is shown welcoming the "49th" state. The movie is set in Hawaii and Alaska is the 49th state. Hawaii gained statehood in August 1959, Alaska in the January of that year.
Factual error: Summer and Carmen are at the saloon and catch on the local news the report of the kidnapping. The scene is set in Tuscany, Italy, but the news anchor is Spanish actress Paz Vega, speaking with an obvious accent and mispronouncing words. To make the whole situation even more absurd, she is supposed to portray a native Italian speaker, "Giulia Carni": the last name is Italian sounding but nonexistent in reality, and the headline used for the news report, "Nonna-napper", "kidnapper of grandmother" has such an awkward and unnatural sound and feel in Italian and for an Italian audience, that nobody ever would use it. (00:37:50)