Continuity mistake: In the beginning of the movie as Captain Willard dances around his room there's a red and white can sitting on the left of his mirror. It's there for two shots but then in the next shot when he busts the mirror it's not there and we see a box instead. (00:06:45)
Continuity mistake: When we first see Captain Willard in the movie he's looking at the ceiling fan spinning above his head. There's only one fan above his head yet we see two different fans in the scene. The first ceiling fan has a different motor and the acoustic tiles show signs of water damage not seen on the second fan. (00:01:50)
Continuity mistake: As Captain Willard stands in front of Lieutenant Colby his hair is soaking wet with sweat dripping off of it. Several seconds later as they look at the severed heads on the steps his hair is dry. (02:33:10)
Continuity mistake: One spear is thrown and it goes through Chief Phillips horizontally, but in the close-up shot of Captain Willard a fraction of a second before the impact we see the spear in a vertical position in front of the captain's face. (02:22:30)
Continuity mistake: Just before Colonel Kilgore gets into his helicopter, he says to the trumpet player, "All right, Son, let her rip!" His left hand moves from being in front of his belt to being at his side between shots. (00:34:45)
Continuity mistake: As Lance prepares Chief Phillips' body for burial at sea his left foot is on the side of the boat. In the next shot of Chef talking to Captain Willard, Lance is already in the water. (02:23:55)
Continuity mistake: When Clean sits down in the back of the boat and opens up the tape from his mom, notice the order of the bullets in the machine gun to the right of the screen. When we first see them they're all packed in order, three shots later as he reads the letter they're uneven though no one has touched them. (01:51:00)
Continuity mistake: Captain Willard reads Kurtz' file and narrates, "Late Summer, Autumn 1968" as Clean drums in front of him. At first Clean has both sticks on the helmet than in the next shot the right stick is on the helmet and the left is hitting the boat. (01:17:20)
Continuity mistake: When the soldiers come to the door with Captain Willard's new orders a green piece of paper (money) appears behind his gun lying on the table under the lamp. It's there in the close-up but not when they first walk in. The other pieces of paper in front and to the left of the gun are also moved. (00:08:20)
Continuity mistake: The guy on the second patrol boat that throws the flare onto their roof starts out wearing a dark green beret, but in the next shot, when we see him up close, he's not wearing any hat at all. (01:16:30)
Continuity mistake: Captain Willard sits down at Colonel Kurtz' typewriter after he reads the manuscript and as he moves into the light we see that his right shoulder is covered with mud. To shots later as he emerges from the temple the mud is not there. (03:11:05)
Continuity mistake: As they approach Kurtz' compound Captain Willard climbs up to the top of the boat. As he's climbing there's no helmet hanging off the light pole in front but in the next shot as he reaches the top a helmet appears. (02:27:40)
Continuity mistake: During dinner Hubert de Marais starts to rattle off all of the places in the world the French have lost wars. In the next shot the wine glass in front of Captain Willard goes from one quarter full to three quarters full between shots. (02:05:30)
Continuity mistake: After the napalm attack we see the back of the PBR as the men prepare to continue up the river. Later we see the back again after the scene at the Do Lung Bridge and the boys have a different boat, which now has three lights on its back section. (00:49:00 - 01:49:10)
Continuity mistake: When Kilgore's chopper lands, Captain Willard is holding his rifle with the strap around his left shoulder so that the butt comes up above his head. In the next shot he's holding it in his left hand and the strap is not around his shoulder anymore. (00:26:40)
Continuity mistake: After shooting up the sampan Clean closes his machine gun twice between shots. (01:37:15)
Continuity mistake: After Captain Willard grabs him the sergeant says, "Would you guys like some seats". If you look at the sergeant's desk one of the two flashlights has fallen and the pencils in the pencil holder are rearranged without anyone going near them. (01:05:45)
Continuity mistake: A soldier walks up to Colonel Kilgore, as he offers the wounded VC soldier water, and says, "I think one of those soldiers is Lance Johnson the surfer". His floppy hat has the name Latigo printed in the dark letters on the back of it. The next time we see the back of his hat when everyone talks with Lance the name Latigo isn't there even though he doesn't touch it. (00:29:45)
Continuity mistake: When Dennis Hopper says, "The heads, you're looking at the heads, sometimes he goes too far, he's the first one to admit it" look at the two cameras around his neck. At first the lenses are both pointing outward then in the next shot he turns around and the left camera lens is pointing at the ground. (02:33:40)
Continuity mistake: Look closely at the shadows going across Chief Phillip's face just before he tries to kill Captain Willard. First they're going from left to right, then in the next shot when he grabs the captain's head, they're going from right to left. This happens several other times in the scene. (02:23:05)
Chosen answer: Kurtz was protected by political connections and his military record from being relieved of command, and the Montagnard people whose village he was in were considered American allies, so they couldn't just send a force in to kill him or relieve him of command, but an individual assassin. (The US Government's "official" policy is that they do not engage in assassination, which is why "this mission does not exist, nor will it ever exist").
Captain Defenestrator