Continuity mistake: Jack hides behind a statue outside the blacksmith shop. The soldiers run past a woman and her vegetable cart whose wheels are closest to the blacksmith shop. After Jack removes his sword, he looks around the courtyard. The cart's legs are now closest to the blacksmith shop and the wheels are now at the other end, the complete opposite of how the cart was positioned in the first shot. (00:20:35)
Revealing mistake: Almost at the end of the movie, after Will saved Jack Sparrow from being hanged, they run to the cliff and they are caught by the Commodore and his men. In this scene there is a close shot of Johnny Depp's face, where you can see that he is wearing contact lenses. (02:08:35)
Continuity mistake: At the end of Jack and Will's duel, Jack says, "Move away," and Will replies "No." In this shot, Will's forehead is bare. Then when he says "No," again, there is some hair over his forehead. After Jack says, "This shot is not meant for you," the hair is gone.
Continuity mistake: After cutting the corset, Jack picks up the medallion in a close-up shot of Elizabeth and her hand is next to her head. In the next wide shot, as Norrington rushes over, her arm is stretched out, up past her head. In this wide shot, the neckline of her slip is different than the two close-ups, before and after. In her next close-up, her hand is back near her head again. (00:16:45)
Continuity mistake: Will goes to the fort and pleads with Norrington to find and save Elizabeth. On the table are two distinct feather quills. They're in different positions in the wide shot and in the close-up when Will slams the axe down on the map. Also, in that wide shot, there is a small bottle in front of the quill holder, whereas in the close-up, the small bottle isn't there. (00:41:40)
Continuity mistake: In the brig aboard the Pearl, Jack sees Gibbs' flask in the pooled water around him. He reaches for it, holds it upside down to his mouth to drink from. There are two successive shots of him holding it to his mouth and then moving it away. The left sleeve leaning on his knee and the position of the long striped cloth that he wears around his waist differs in both shots. Also, the item on the floor to his left is in a different position in both shots. (01:25:55)
Continuity mistake: Ragetti gets hit in his wooden eye with a fork, which would cause enough damage to be noticeable but no damage is ever visible.
Revealing mistake: In the wide shot of the Black Pearl chasing the Interceptor, because of its sailing speed the flag at the stern of Interceptor is upright and blowing hard into the wind. Aboard the Pearl, when Barbossa looks straight ahead at the 'speeding' Interceptor, the flag is down and not blowing at all. (01:22:55)
Other mistake: Ragetti's wooden eye always moves in sync with his real one. At that time, a prosthetic eye (wooden or otherwise) would remain stationary or move around independently from the real one. Even if this is a magical benefit of his 'cursed' state, it still moves in sync when he's transformed back into mortal form. (00:30:45)
Continuity mistake: In the beginning, after the young Will is pulled on board, when Will says his name, the medallion is protruding out of his shirt. After young Elizabeth tells him, "I'm watching over you Will," in the next shot of Will, the medallion is completely hidden in his shirt, and his position differs between shots. (00:03:50)
Continuity mistake: At the opening of the scene in the cave of treasures, Jack lifts up a well endowed golden statue, looks at it awhile and tosses it back into the pile, as he clues Will with talk of honesty and dishonesty. Later in the scene, Jack and Barbossa are fighting in front of that same pile and the golden statue that Jack had thrown earlier is now sitting upright behind the chandelier. (01:51:40 - 01:52:40)
Continuity mistake: When Elizabeth is hiding from the pirates in the closet, and the pirates first enter the room, you can see that the carpet is folded back (from her opening the door) quite a bit. When the pirates see the carpet pushed back and know where Elizabeth is hiding, just a small corner of the carpet is pushed back. (00:33:35)
Continuity mistake: Will comes into the blacksmith shop, comments about Mr. Brown and then approaches the anvil. In this shot the wood post on his right has a hammer and knotted rope hanging together on the same side. However, later when Jack sprays the soot at Will the same wood post is seen on Will's left and the rope hangs on another side of the post, not together with the hammer. That rope changes shape and position in other shots in between too. (00:22:15 - 00:26:15)
Audio problem: Aboard Interceptor after the downed mast, Will is trapped below deck, as Elizabeth yells to him, "I can't move it," then Grapple and Mallet grab Elizabeth and she screams, "Will!" In the next shot of Elizabeth, she fights to free herself and we hear her scream, "Will!" again, but she's clenching her teeth and her mouth doesn't form the word Will. At almost the same moment that she screams, "Will!" the second time, Cotton's parrot squawks. (01:29:30)
Continuity mistake: Anamaria has her hands on Jack's shoulders in the front shot, just as she said, "The Black Pearl is yours," and then she removes her hands. In the next successive side shot, her hands are still on Jack's shoulders, she then removes them again as she smiles at him. Jack's left sleeve is different in both shots. (02:12:15)
Continuity mistake: As the soldiers are firing at Jack after his escape, he runs across the footbridge. In the far wide shot, he crosses the center of the bridge and passes the man with the sack on his back. In the next close-up shot, Jack is just getting to the center of the bridge and starts to pass the man with the sack on his back. (00:20:20)
Continuity mistake: When Mr. Gibbs yells, "Load the guns! Case shot and langrage!" Will is behind him in this shot and Will's body is facing towards Anamaria, yet in Will's close-up, his body is facing towards Mr. Gibbs, and just then turns a bit, to face Anamaria and Elizabeth. (01:23:25)
Continuity mistake: When Jack hangs onto the beam and then in some close-ups while up on the beams, as he and Will are fighting, the large bandana around his head is soaked at his forehead. However, when he holds the gun on Will, the bandana is completely dry. (00:25:55)
Audio problem: In the scene where Jack is to be hung, there is an official reading off the list of Jack's crimes. In the shot over Will's left shoulder, you can see the reader in the upper left hand corner of the screen. In that shot, you can see that his mouth is not in sync with his words. (02:04:50)
Continuity mistake: Just before Will sends Jack up to the rafters, A close up of Jack's face shows a single hair going across his right eye. And then it's gone as he's sent up from close up. (00:25:50)
Answer: The curse needs the blood of everybody who took a coin from the chest. All the other pirates have already contributed so, as the movie opens, the only blood needed is Will's, substituting for his father. During the finale of the movie, Jack takes a coin from the chest, adding himself to the curse, so his blood is now required as well as Will's.
Tailkinker ★
But I didn't see any blood on the coins, and none of the pirates cut themselves, even before Will became part of the mix.
Yes, the other pirates did cut themselves before Will came into it, off-screen. The lack of blood on the coins can simply be explained as most of it dripping to the bottom of the chest, it being washed away by storms blown into the cave, or by the fact that they didn't drop that much blood on it in the first place.
When they had Elizabeth they believed she was Bill Turner's daughter, but they all thought the curse had failed, none of them had cut themselves so it makes zero sense.
They had been collecting back the coins for years. During that time they repaid their own blood. All they needed was the last coin and the blood of Bill Turner to break the spell.
lionhead