Continuity mistake: 1955-Jen is showing some dresses to a friend when Biff shows up. Watch the man passing by the girls. He walks by twice.
Continuity mistake: Inside the tunnel, Biff punches Marty who's on the hoverboard, launching him back. A shot later Marty is suddenly standing tall and next to Biff, and gets punched again.
Continuity mistake: When 1955-Marty reads Doc's 1885 letter next to the Western Union car, his right hand is either on the lower part of the paper or the upper, depending on the shot.
Continuity mistake: When Doc travels to 1885, Marty stands on the road holding a rope and says "He's gone." When the angle changes, the length of the rope sticking out is much shorter. (01:38:03)
Continuity mistake: When 1985-Jen encounters her old self, 2015-Jen walks several steps further. When the angle changes, old-Jen has stepped back 4 meters to allow for both to stare at each other closely.
Continuity mistake: When 2015-Lorraine takes the pizza out of the oven, the amount of green peppers decreases between shots. (00:33:22)
Continuity mistake: When Jen finds out that she got married in the chapel of love, her hair swaps from perfectly brushed to totally messed-up between shots.
Revealing mistake: Doc and Marty hide in the alleyway while the flying police car takes 1985-Jen home. Problem is, Doc stares in awe at the sky before the police car is in view.
Continuity mistake: After Jen is taken to her home in the future, Marty and Doc are in the car. Doc places his left hand over his glasses, but when the shot changes he's got his pinky finger raised.
Other mistake: Griff enters Cafe 80s and tells Grandpa to wax the car. Grandpa stands up and walks to the door, but Griff keeps looking at where he was standing before. This was due to the VistaGlide system of filming an empty space without stunts that could serve as cues as to where to look at.
Continuity mistake: When Marty reads the paper with the news about his son's arrest, the way he holds the paper differs between shots. (00:09:44)
Continuity mistake: At the beginning of the movie when Doc smashes through the trash cans, his glasses are not on. In the shot where he steps out of the car they are.
Suggested correction: He put them on in between shots.
Continuity mistake: During the beginning of the chase sequence, Marty is hanging on to a rope and there is a rear facing shot looking at him. There are two wet tire tracks in the shot. These disappear in the following shots.
Continuity mistake: When Doc turns the time circuits on as he is about to head over to the high school, the 'Destination Time' is under 'Last Time Departed', but in the next shot, it is back to being over it like normal. It should also be noted that the month is represented by a number in the first shot, but with letters in the second. Additionally, one of the LED's is burnt out in the first, but is back to being lit in the second. (01:23:30)
Revealing mistake: When Doc holds the newspaper with the 'Gang jailed' headline, the same paragraph is repeated several times. (00:24:03)
Revealing mistake: When old Biff turns to face Griff, his elbow passes through Marty's Pepsi bottle. (00:14:41)
Continuity mistake: While Marty gets to 2015 it's raining and the streets are wet, but when Griff's gang is chasing him the streets are dry.
