Continuity mistake: They took the flag from the PBR (which is removed from the roof of the boat the next time we see it) to cover Clean's body at burial. It's not the same flag, the last red stripe on the bottom of the PBR's flag is torn off as we see at the French Plantation dock. The flag on Clean's body has the last red stripe and also has a shorter white stripe on it's bottom. There's no indication that there is more than one flag on the PBR (redux version). (02:00:05)????
Audio problem: On the French plantation dock Captain Willard walks over towards the Frenchman and they do an excellent job of overdubbing the sound of his helmet strap each time it hits his chest. Two shots later they don't put in the sound as the helmet strap hit's against his chest several more times. (01:58:00)????
Continuity mistake: The entire French plantation dinner scene is beautifully lit. It looks as though it's sunset until Hubert walks over to the window in middle of the scene. As he stands by the window we can see outside and it's not sunset but midafternoon. Then as he walks to his seat he passes back into the yellow stage lighting again which makes it look as if it's sunset. (02:08:50)????
Continuity mistake: As Hubert stands at the window he says, "The generals and the colonels believe it's impossible for the Viets to get the cannons up there in the mountains". It's clear to see that all the windows are closed but the next time we see them the second one from the bottom is open even though no one has gone near them. (02:08:55)????