Revealing mistake: Aboard Interceptor, Jack calls out, "Monkey!" as the monkey jumps onto the broken mast leading to the Pearl and Jack runs after him. In the very next shot of Elizabeth, who's trying to move the broken rigging from the hatch that Will is trapped under, the coloring is off in this one shot. The color of her dress, for example, is not vibrant, it is brown. This is visible on the region 1 DVD and on videotape. (01:29:25)
Revealing mistake: Before Interceptor's explosion, in the close-up it's very apparent that it's not the real Interceptor. Some examples are, no rigging at the stern-most mast, at the railing there are no belaying pins with or without all the lines hanging from them, there are no cleats with or without lines and at least two of the swiveling mounts at the stern for the swivel cannons aren't there. (01:30:40)
Revealing mistake: When Elizabeth gets out of the water on the little island, you can see a modern day bra through her dress. (01:31:25)
Revealing mistake: When Jack is aboard the Black Pearl, as Will makes demands we see Jack's very grimy hands and dirt embedded fingernails. Jack dives and retrieves his sword and gun underwater, and when he does the hands that lift the sword and gun underwater are perfectly clean and have very well manicured fingernails. Once on the island, his hands are as grimy as they were on the Pearl and his fingernails are once again short and dirty. (01:34:50)
Revealing mistake: In the close-up of Jack as he swims to get his gun, etc, his left sleeve is pushed up and it's very obvious that he's wearing something with short sleeves under his white shirt. This isn't part of his white shirt. He has nothing on under his white shirt at any other time. (The underwater close-up of Depp was filmed in a tank at Long Beach along with the close-ups rescuing Elizabeth earlier.) (01:34:50)
Revealing mistake: Jack and Elizabeth are marooned on the island, and he goes down the stairs to the cache of rum. From below, he lifts his right arm up holding a bottle of rum and we see the pirate brand. It's a CG brand, and in this shot, the pirate brand is crooked and off to the side. It doesn't look the same as the close-up when Norrington lifts Jack's sleeve in Port Royal, and it's not because of camera angle. Jack's sun and sparrow tattoo isn't where it's supposed to be either. At this point in filming, this 'tattoo' on his arm is not a real tattoo, it is only applied for specific shots, and make-up didn't apply it for this shot. (This has nothing to do with Depp's real tattoo that he supposedly got later, after filming.) (01:36:15)
Revealing mistake: When saying, Welcome to the Caribbean, love," Jack, who is beside Elizabeth, starts to walk past her and his right hand nudges her left arm, to move her away. In the next close-up, taken later as a studio pickup, it shows him instead handing the bottle of rum to Elizabeth. In the close-up it's not Depp's hand on the rum bottle - the fingers are short and stocky, whereas Depp's are long and slim. Other differences between the outdoor and studio shots include, Jack's red string tied to his braid, Elizabeth's hair is not as messy and windblown, etc. (The original scene is shown in the deleted scenes.) (01:36:30)
Revealing mistake: When Jack and Elizabeth are marooned on the island, Jack wants to know why the rum is gone. Elizabeth sits down in front of Jack, and as he stands behind her, he puts his fists up to his chin in frustration. His right forearm does not have the sun and sparrow tattoo showing, although part of it should be. The entire tattoo would not be hidden under his sleeve, makeup simply did not apply it for this shot. (01:39:20)
Revealing mistake: When Will uses skeletal Jacoby's sword to skewer the other skeletal pirate, he runs behind Jacoby to avoid being slashed and ducks. However, as Will looks at the pirates, his eye contact with the two skeletal pirates and their weapons is not in sync with them. Since they are CG, they were not there during filming, same as the shot of the three skewered pirates. (01:56:35)
Revealing mistake: Jack says, "Or you could surrender." Soon after, Barbossa smacks Jack in the face and we can see Jack's wig and red forehead scarf coming off his head, as he's going down. You can clearly see Tony Angelotti's (Depp's stunt double) forehead, sideburns and hairline in the right hand corner of the screen. (The shot right after this one is Jack running with his arms waving.) (01:57:15)
Revealing mistake: After Will slams the gold bowl down over the pirate's head, this pirate spends time trying to pry the bowl off his head with great difficulty. When Jacoby tosses the bomb, Will dives, then lands and seen in the background is the gold bowl pirate. The bowl actually starts to FALL OFF his head, so the actor reaches up with his left hand to keep it on his head for the shot. However after Elizabeth asks, "Whose side is Jack on?" the pirate is very pleased with himself when he is finally able to pry the bowl off, just before Elizabeth whacks him. (01:59:35)
Revealing mistake: After skewering the three skeletal pirates, Will places the lit bomb inside of Jacoby. In the close-up Will places the bomb through Jacoby's ribs, right under his beard and Jacoby's leather strap and buckle are not seen. Yet in the next shot as Will removes his hand, the strap and buckle are slung across Jacoby's ribs near his beard. It should have been seen in the close-up. (02:00:30)
Revealing mistake: When Jack sees Will run toward the Aztec chest, he quickly slices his palm and parries with Barbossa. In the shot facing Barbossa, Jack strikes the sword out of Barbossa's hand, then as Barbossa spins around his right hand is empty, and we hear the sword falling in the distance. However, when Barbossa says, "Ten years you carry that pistol..." Barbossa is still miraculously holding his sword - the sword tip is moving at the bottom of the screen, as he speaks. (More of the sword is visible on VHS.) (02:00:45)
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)
Revealing mistake: When the Black Pearl swings alongside the Interceptor for the battle, Elizabeth shouts, "Fire all!" The next shot is from behind the lit cannon which is aimed at the Pearl and the following shot faces the Interceptor's cannon, as it goes off. In the shot facing the Interceptor, the raw wood scaffolding type beams are perfectly visible at the entire lower part of the screen, where the painted planks (below the gun ports, above the bilges) of the hull should be. (This is only visible on the video version.)
Revealing mistake: When the Interceptor's clubhauling and it shows the stern out of the water, it's obviously a model (although there was a real ship, they used a model for riskier scenes).
Revealing mistake: After Will throws the small axe at the pirate and it hits him, he picks it up again and runs away. But the axe has no blood on it. The pirates do leave blood on weapons, as shown when Elizabeth stabs Barbossa later.
Revealing mistake: The cannonballs are solid balls and not self-exploding cannonballs (as can be seen from the handling on board of the Pearl). As such they cannot explode when they hit a target. Even if they were self-exploding cannonballs, they would simply explode and not cause yellowish fire flares around them. The type of fire that is seen after impact comes from a liquid, not anything made of powder (particularly noticeable with the cannonball that hits the prison that lets the prisoners escape).
Revealing mistake: When Captain Jack and Will are walking in the upside down boat, from the outside it looks like it's made of fibre glass rather than wood.
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