Charlie Goes America All Over Everybody's Ass - S2-E9
Audio problem: When the Vietnamese man is playing Russian Roulette in the end, a few seconds after picking up the gun, he moves his thumb and we hear the gun cock. However, you can see that he didn't actually cock the gun, as his thumb never came into contact with the hammer while moving, hence the sound was a phantom sound.
Charlie Goes America All Over Everybody's Ass - S2-E9
Continuity mistake: At the beginning, the position of Dennis holding his cigarette changes between shots. For example, when Dee says "thank you", Dennis is putting the cigarette down, and then in the next shot when Charlie walks in, Dennis has his hand back up and is putting the cigarette down again.
