Back to the Future Part II (1989)

Continuity mistake: When Marty confronts Biff in the alternate 1985 in the hot tub, the girls change positions. The blonde was on his left and the brunette was on his right. When they see Marty and scream, they move forward but there is no way they can switch that fast. (00:55:40)

Audio problem: When Marty is watching himself talk to Lorraine after playing Johnny B. Goode, you can see and hear Lorraine, "I hope you don't mind but George asked me if he could take me home" but watch her lips and listen. It's way out of sync.

Audio problem: When Marty follows Biff into the dance hall trying to get the sports almanac, right after he uses his binoculars he exits the dance hall. If you listen carefully to the music, the music plays uninterrupted, when given the jump in scene it should skip to a further point in the song.