Force 10 from Navarone (1978)

Revealing mistake: In one of the river flooding scenes after the dam bursts, you can see a modern day vehicle (most likely a pickup truck) for a few seconds on a highway next to the river. (01:50:30)

Maj. Schroeder: Ah, tell me what has all this to do with that, uh, suitcase case you keep looking at?
Mallory: Well, that suitcase is full of our penicillin.
Maj. Schroeder: Oh, indeed. Perhaps I could see some it?
Mallory: Certainly, Major. Open it Miller.
Miller: You can't do that here, sir. You'll ruin the lot. You know perfectly well that any contamination will destroy it. It's got to be opened under laboratory conditions.

Trivia: The Chetniks were not one coherent group, as portrayed in the movie. There were in fact two opposing fractions: the first fought alongside the partisans, the others - founded by Kosta Pecanac (the featured group) cooperated with the Germans. Despite their public enmity, though, they still maintained good relations with each other, one of the facts which led to great confusion about the Chetniks among the Allies - probably the reason why they are portrayed here solely as 'bad guys'.