Continuity mistake: Captain Willard tries to stop him from shooting but Chief Phillips yells, "you son of a bitch" as he pushes the captain to the floor. In the next shot the captain is up and holding onto the roof of the boat with his left hand. (02:22:25)
Continuity mistake: In some shots of the helicopters as they approach Vin Din Dop they're above the clouds, but in successive shots they're at or near ground level. (00:38:35)
Other mistake: Kilgore watches from the beach after he calls in the napalm attack on Vin Din Dop. We see a large explosion but the three fighters never actually drop any napalm, they just fly over. (00:48:50)
Continuity mistake: Right after the napalm explosion there's a wide shot of the beach as Colonel Kilgore and the two soldiers with him look across at the destruction. We also see Lance sitting alone in the crater and Captain Willard is nowhere near them. They cut away to the PBR for three seconds then back to the crater and the Captain is sitting next to Lance again. (00:48:55)
Continuity mistake: As they start to eat with General Corman there's a hat hanging on a cabinet behind and to the right of the general and both doors are closed behind it. The next time we see it the right door of the cabinet has been opened but no one went near it. (00:11:45)
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)
Audio problem: When Clean says that great line, "Well I'm next ma'am," to the Playboy bunny, he also says something else that was edited out. (01:32:50)
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: As "Satisfaction" plays in the background Clean dances behind Chief Phillips as he controls the boat. In the next long shot of Lance water skiing past the Vietnamese on the shoreline Clean is not there. (01:14:45)
Continuity mistake: As Captain Willard sits in the boat looking at pictures of Colonel Kurtz the shadow of a metal bar slowly goes from left to right across the pictures indicating that the boat is turning. In the next shot of Clean dancing to Satisfaction we can tell by looking at the sky that the boat is not turning but going straight ahead. (01:15:15)
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: After shooting up the sampan Clean closes his machine gun twice between shots. (01:37:15)
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: 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 vehicle on the Vin Din Dop bridge is shot by a rocket from Kilgore's helicopter and Lance says' "nice shot Bill" after he sees the car blow up. Colonel Kilgore's helicopter has surfboards on its sides not rocket launchers as was seen when they took off in the last scene. (00:41:45)
Continuity mistake: Chief Phillips says, "Lance, take a 16 on the bow," and we see him walk to the front of the boat past the spot where Captain Willard was hiding for cover during the attack that killed Clean. The molding was blown off by machine gun fire during the attack, but now it's good as new. (01:55:30)
Continuity mistake: No one goes near them but as Chief Phillips tries to kill Captain Willard the pile of arrows on the floor of the boat to the left of Phillips' head are rearranged differently between shots. (02:22:55)
Continuity mistake: During the arrow attack as Chef is firing the rear machine madly Captain Willard walks from the front to the rear of the boat to try to stop him. Just as he swings into the back part of the boat he slips and falls backwards. In the next shot he's up and running toward Chef. (02:21:50)
Continuity mistake: When Colonel Kilgore shows Lance the surf as they fly over the beach he says, "look, good six-foot swells" and his surf board is not on the side of his helicopter as it is in the next shot when they land. (00:45:10)
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