Plot hole: If Bradley Cooper was able to "quintuple" his money every day in the market as he claims to have done, he would have been able to earn the $100k he borrowed from a loan shark within a few days, starting from $800. Alternatively, he is shown in one scene winning a pot in poker where he could presumably also make a large amount of "seed" money from gambling. There was no need to borrow such a small sum of money from a loan shark, making the entire sub-plot unnecessary.
Factual error: In the scene straight after the opening credits we are taken to Baker Street where construction work is being done. This work is identified by a sign with a logo as being for the underground line. The logo type face was developed by a Mr. Edward Johnston for London Underground from 1913 but the distinctive typeface used in the film was not in place until 1919. This is obviously long after the 1891 setting of the film.
Continuity mistake: There is a scene where Hugo is on the station and sees a key down on the tracks. There are two seperate shots of the key and both times it is buried in the stones next to a sleeper. Then Hugo jumps down onto the tracks to pick it up and its now quite sat on the middle of the sleeper when he picks it up. (01:22:30 - 01:23:10)
Continuity mistake: The overall timeline of the film is about twelve months but it is inconsistent as far as the seasons. When Blomkvist arrives at the Vanger's island, it is the dead of winter with deep snowfall. A short while later, when Blomkvist is talking to the detective on a pay phone (who asks if he is surviving the winter weather), the snow is gone and the deciduous trees have no leaves, but a few minutes later, when the scene cuts to Henrik Vanger being rushed to the hospital, it is suddenly the middle of summer, sunny and the trees are in full bloom. When Lisbeth arrives on the island, and she and Blomkvist are sitting outside at night talking, the trees close to the house are bare and a howling wind can be heard in the background, but the next day trees have leaves. Some weeks later, when Lisbeth saves Bloomkvist from Martin, it is winter again, with heavy frost on the ground and trees are bare once more. A little while after that, when Lisbeth and Blomkvist go to find Harriet, trees on the street are in full bloom. A day or two later, when Blomkvist is talking to Harriet in the park, it is apparently now early spring because the smaller deciduous trees are only just beginning to sprout new leaves while some bigger ones have none at all. At the very end, it's just before Christmas again.raywest
Character mistake: When the EMTs are resuscitating Dr. Harris, they use a defibrillator despite their being on a wet metal dock. Not only is this highly dangerous to absolutely everyone present, it would be completely ineffective at restarting his heart as the water and the metal would dissipate the electric current too much for it to do any good. At the very least, they would have stabilized his spine then moved him to a dry surface before beginning defibrillation. (00:08:30 - 00:09:10)Phixius
Factual error: Near the end of the movie, when they go to steal the boat, there is a Puerto Rican flag in the front of the boat. This flag has the royal blue triangle, instead of the light blue that would have been in the 1960's such as all the other big flags used on poles.
Factual error: The character Peter has a modern haircut that would not have been found during medieval Europe; his hair defying gravity despite being a time without hair gel.
Plot hole: The very last scene shows Mary building a wall, apparently in her belfry. But there should still be the original wall that Rose built, with the hole in it that Mary smashed in. By killing Rose / having killed Rose, she prevents further harm, but all effects that took place before that (also the building of the wall), should stay (like her scars).It is very unlikely Mary broke down the whole wall just to add another body. (01:28:25)Alpha23
Revealing mistake: When Donovan witnesses a fatal traffic accident on a rainy night, he suffers a mild heart attack and collapses in the street. Although he's lying on his back, unprotected from the downpour, surrounded by rain striking the pavement in both foreground and background, closeups show that no rain strikes his face, his felt hat, or his clothing. (00:12:20 - 00:12:50)Charles Austin Miller