Factual error: When Marty hits his head on the DeLorean's steering wheel, the car's horn honks. This is inaccurate to the design of real-world DeLoreans, as a DMC-12's horn button is actually located at the end of the turn signal lever rather than in the steering wheel. (01:39:27)
Suggested correction: You can't see his left hand and he could have accidentally pushed it when he hit his head. Or Dr. Bown customized the steering wheel so the horn is in it, like he customized the entire interior of the car.
I thought the point was that the car was so unreliable that when hit his head on the steering wheel, the horn went on. Makes sense to me. I own a DeLorean by the way.
Revealing mistake: When Marty crosses the park in front of the court house and the camera pans around following Marty while showing the town, watch one of the buildings in the middle background. Part of the building is grey and has 2 windows and is supposed to have a slanted roof, but if you watch closely, it appears that building is in fact only a wall with nothing behind it. (00:34:40)
Suggested correction: Nothing really specifies that the building is only a wall. It definitely could be, but since there are no camera angles showing the back or sides of the building, it's not really fair to call this a mistake.
Continuity mistake: When Marty is riding his skateboard to school in the beginning, he waves to a driver and you can see his wearing a watch on his left hand. However, look at his left hand when he meets up with Jennifer, and you'll see that it's gone. (00:06:10 - 00:07:00)
Suggested correction: There's a time-lapse directly before Marty arrives at school. There was plenty of time for him to remove the watch offscreen.
Trivia: The town hall building is also seen in the Voyagers TV show.
Suggested correction: The Town Hall building is in over 100 movies and TV shows since it is a building in Courthouse Square at Universal Studios. It has also appeared in Gremlins, The Twilight Zone, To Kill a Mockingbird, Knight Rider, Leave It To Beaver, Parenthood, Saving Mr. Banks, and Psycho II, to name some of a few of the more commonly known. I don't think its common appearance makes this trivia relevant.
I'd say it makes it more relevant. Just add the multiple appearances of the building.
Deliberate mistake: The sequence with the Libyans chasing Marty at the end of the film is much shorter than the original chase.
Suggested correction: It just seems this way. In the original chase, we switch back and forth between two different viewpoints, inside and outside the car. This falsely exaggerates the duration of the chase, as the two things are happening simultaneously rather than in sequence. The second time, the chase is only shown from the external perspective, giving a more realistic perspective.
Continuity mistake: As Doc turns the plutonium jar on the back of the DeLorean, the little thing sticking out of the jar slides greatly down, without any motion of moving. (00:27:15)
Suggested correction: Wrong. It does show motion as it slides down, it just moves very quickly.
