Continuity mistake: Ellis leaves in in his dad's Jeep (model year 2005-2007) and in the very next scene he is driving a newer model.
Continuity mistake: The morning after Christian brought a drunk Ana back to his hotel room, she is sitting in bed eating some breakfast. The piece of toast she is holding keeps changing shape, having one bite taken out of it, then two, then one again in a different pattern.
Continuity mistake: When Anna Kendrick is making pancakes for her friend, in a shot of her from the front she isn't wearing her necklace, but in the second shot it shows her wearing it again. (00:24:35 - 00:26:15)
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.
Continuity mistake: When the woman is eating the bread roll on the train, the end of the roll switches from uneaten to having bites taken out of it and back again.
Continuity mistake: The first time we see Roland on his own at the bar, he's talking with the bartender, Michel. When he asks Roland in French where his wife is, Niels Arestrup's arm changes position instantaneously in an edit mid-sentence, and does the same a couple more times after. (00:11:30)
Factual error: Jack's RAF uniform is wrong on a number of levels. He is not wearing the eagles at the top of each sleeve worn by all RAF airmen. He is not wearing the correct Air Gunner brevet (with a single wing), but in fact wears a made-up badge that is claimed to indicate he has shot down five enemy aircraft. He does not have a cap badge on his forage cap.
Continuity mistake: When Killian is at the dinner party, in the first wide shot of the table, Killian is shown sitting at his seat, holding a fork, pointed in a downwards position. Then it cuts to a shot focusing on Killian, where the fork is now being held at a sideways position. (00:26:06)
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.
Continuity mistake: When Zipper drops her off at her car at the beach, Marnie is wearing boots when she gets off his motorcycle. When she walks to the car she's wearing shoes.
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)
Continuity mistake: Charlie's mock trial: the latina maid walks up the stairs, with Sebastian saying "OhmahGod, thank you." In the foreground, London is holding her goblet with her right hand, but in the next shot she has it in her left. (00:05:15)
Other mistake: Whilst the main character is having a 'talk' with the general, the world clocks on the way show 3:50 on time 1, and 3:49 on time 2. (01:25:10)