Continuity mistake: In the very beginning of the movie priest Vallon is shaving. The reflection in the mirror shows a wispy, short mustache, but when we see Vallon's face as he speaks to his son his mustache is thick and twisted. (00:01:40)
Continuity mistake: As someone pointed out earlier, the poster for the commemoration of the Five Points battle claims to be the 16th anniversary, but the date shows 1863 -- 17 years after the 1846 battle. To further add to the confusion, when William Cutting is talking to Amsterdam in the bedroom after the night at the brothel, he says, "I killed the last honorable man [Priest Vallon] 15 years ago [in the Five Points battle]." So which is it? 15, 16, or 17 years? (00:02:42)
Continuity mistake: Before the big battle of Five Points begins Bill's gang comes out from a decrepit house. In the first wide shot of the place there is no smoke coming out ouf the chimney of the adjacent house to the right, but a moment later when Bill's people start to emerge it's smoking heavily. (00:06:00)
Revealing mistake: In the beginning of the Five Points battle it happens very often that people get hit badly with a sharp weapon but don't receive any wound. Watch for example in slow-motion how Bill sets out to mow down victim after victim with his cleaver. Later into the fight it becomes a lot bloodier, and sometimes the blood seems to come out of the weapon (e.g Monk's club seems to have a generous blood reservoir). (00:08:15)
Continuity mistake: In the battle of Five Points a witch-like women with steel claws jumps at a man, already flashing her teeth in anticipation of a good bite. Before she lands on him she lowers her head that it ends up below his shoulder, but when the camera angle changes she's biting off his ear. (00:08:50)
Revealing mistake: In the middle of the battle of Five Points Monk swings his club horizontally at shoulder level, but the swing ends on a victim's ankle. When the bones break it's very obvious that it's a prop. (00:09:15)
Revealing mistake: In the battle of The Five Points, there are at least two instances where you see "blood" splattered over the lens. (00:09:35)
Continuity mistake: The moment when Bill attacks Vallon is very badly edited. There's a shot of Bill raising his cleaver, and it must be at Vallon because he had his eyes fixed on him already for a while. Then you see Vallon's arm crushed by a halberd, then again Bill staring at Vallon, then Vallon turning around, unharmed as it seems, and finally Bill slashing Vallon with his cleaver. (00:09:55)
Continuity mistake: At the end of the Five Points battle, when the defeat of priest Vallon is announced, there are some shots of his shocked followers. In one you see Monk with a pretty clean face, but when the camera closes up on his face it's full of measles-looking blood stains. (00:10:35)
Continuity mistake: When Vallon lies on the ground after Bill has stabbed him he is tightly surrounded by people. When you see his son holding on to his dying father you should see other people's feet, but there aren't any. Also from the lighting of the scene you can tell that these shots were taken with no crowd around. (00:11:00)
Continuity mistake: In Vallon's death scene the blood streaks on his face change in at least three ways, most visibly those on his right cheek. Also the shaving cut he had inflicted on himself before the battle vanishes between two shots. (00:11:45)
Continuity mistake: After young Amsterdam grabs the knife his father was killed with he runs into the Old Brewery. You see his friend Johnny coming from inside while Amsterdam is running up the steps. Then a cut on Bill, then back to the brewery door, and Johnny emerges from the dark again calling out for his friend, and in this shot Amsterdam hasn't even reached the steps yet. (00:13:10)
Continuity mistake: When we see young Amsterdam run off with the knife that was used to stab Priest Vallon, he puts the knife into a little cubby hole in the floor. 16 years go by and we see Amsterdam as an adult return to the same cubby hole, but this time when he pulls out the knife it is wrapped in some type of a cloth. (00:20:30)
Factual error: In one scene where Bill is in the Mayor's office, the mayor is sitting behind his desk and holding a bunch of papers, and on the upper right hand corner of the papers is a paper clip. Paperclips were not invented until 1899. (00:21:15)
Continuity mistake: When Amsterdam arrives in New York City and is talking to his new friend, the bag he is holding switches from being held under his arm (camera shot from front) to being carried on his back (camera shot from the back). This happens at least four times in a row during the same scene. (00:22:55)
Continuity mistake: When Amsterdam and Johnny are looting the burning house Johnny gets trapped by a burning beam. Amsterdam can't make up his mind if he should continue the robbery or rescue his friend, looks at a heap of jewelry lying on the floor, then at Johnny, and when he grabs some pieces before he comes to his help there are only a few scattered around. (00:28:55)
Continuity mistake: In the scene where the future Ghoul Gang shares the booty, Amsterdam provokes the leader who is sitting down while the others are standing behind the table. The guy jumps at him, while the others stay where they are, but before he reaches Amsterdam the others guys separate them, emerging mysteriously from the sides. (00:30:20)
Continuity mistake: When Amsterdam is in the Chinese ballroom the first time, he shows an unfolded sheet of paper with a drawing to the man sitting across the table from him. In the next shot, he hands the paper - which is now folded - to the man, who then unfolds it. (00:33:30)
Continuity mistake: At their first encounter after Amsterdam's return to New York, Bill asks him to come closer. Amsterdam comes around the post he was leaning on, then the camera cuts to Priest Vallon's picture, and when Bill says it's close enough you see Amsterdam coming around the same post again. (00:35:15)
Revealing mistake: When Amsterdam meets Bill for the first time as an adult Bill is playing Whist. Because he is pissed with a guy whose bet isn't high enough he pulls his knife and pins the man's hand to the table. When he does so the hand isn't anywhere near the point where the knife goes in, and when Bill pulls out the knife again you see that it was stuck in the table and the man's hand was resting next to it. (00:36:00)
