Question: I'm not going to list this as a mistake since apparently it didn't happen, but George obviously changed his, his wife's, and Biff's future (at least) when he knocked Biff out in 1955. Since right there the timeline would have changed, what are the odds that Marty would still have been in the parking lot driving from the Libyans and going back to 1955? Couldn't Marty have accidentally caused a paradox to destroy the universe?
Question: In this film, Marty suddenly appears and spends one week in 1955. So, how does Marty freely roam the hallways and cafeteria at Hill Valley High School (even getting into a physical altercation with another student) without challenge from teachers and administrators such as Mr. Strickland? All the kids are talking about Marty, but nobody in authority questions the fact that he's not enrolled, he's completely undocumented, he doesn't attend any classes, and he's apparently a troublemaker.
Question: At the dinner table in 1955, Marty's grandfather is there. It has always appeared to me that there is something off about his appearance. He seems to appear as if he was not actually there, and that he was spliced into the footage from another movie. The lighting on his face, his style of hair, the quality so to speak of him, just seems off from everyone else. He almost seems like he is from a black and white movie, spliced in and colorized a bit Is it supposed to be that he was to look this way, or did they actually take this actor's scene from another movie and splice it in?