Continuity mistake: Kilgore is talking about how he wants to surf the beach. The lighting changes significantly in the space of seconds from the shots of the surf to the shots of the fighting. The shots of the surf are later in the day while the angle of the sun in the fighting shots is higher indicating afternoon.
Continuity mistake: When Willard has a severed head dropped on his lap, the stump is clean and flat like it was sliced by a samurai sword. When the head falls to the ground, the stump is bumpy and ragged like it was hacked with an ax.
Continuity mistake: Close to arriving to the French plantage, and also when leaving it, Captain Willards' helmet cover changes between a plain olive green and a camouflage.
Answer: It should be noted that "transmutation" is a word Coppola has used to describe the film making process. Https://m.youtube.com/watch?v=LFTQcwgq4CY.
Bishop73