Continuity mistake: Right when the movie begins, a machine opens a dog food can and then pours it in the dog's bowl. When pouring the food, the can isn't moved around at all, but after the food drops, the label is missing a piece. (00:02:25)
Continuity mistake: After the clock tower's ledge breaks and Doc's hanging off the edge, we see a shot from below, then of Doc looking straight up at the clock, which changes to 10:03. But look at the clock in the below shot: the minute hand ticks over behind him, then moves again in the close-up. (01:34:00)
Revealing mistake: After Doc sends Einstein back in time, it shows fire trails on the pavement. Marty's leg is right in a (superimposed) flame, with no ill effects at all. (00:21:05)
Continuity mistake: When Martly finishes his rambunctious guitar solo at the dance the camera pans the crowd. In the distance on the left we see Mr Strickland uncovering his ears. After this they show a close up of him uncovering his ears again. (01:25:55)
Visible crew/equipment: At the end of BTTF they all pile into the DeLorean which reverses up to the camera where the matte box and what looks like the top of the cinematographer's head are reflected in the chrome number plate. (01:46:50)
Continuity mistake: When the JVC recorder is first played, the screen on the TV is a blue colour. Later, when Doc is playing the Libyan part again and again, the screen seems to be a brownish colour. (00:50:10 - 01:05:40)
Continuity mistake: After the scene where Marty and his band are rejected from the school tryouts, Jennifer and Marty are sitting down and a lady comes by and asks them for change to save the clock tower. After they attempt a kiss, Jennifer's dad calls for her from the car. In the background, an African-American man is standing looking in the window of a building, and then walking right. In the next shot, he has moved all the way to the left and is walking right. (00:10:30)
Continuity mistake: When Marty is filming the Doc in the parking lot, Doc says that he needs '1.21 gigawatts' to power the time machine. Marty then says 'Doc, you don't just walk into a store and buy plutonium.'. However, when Marty and the Doc of 1955 are listening to it on his TV, the Doc keeps talking after he says '...of electricity I need'. (00:26:35 - 00:53:05)
Continuity mistake: When Marty is using the phone to call Doc while he is in the diner, his watch (which is on his left arm) starts beeping and the guy behind the counter gives him a strange look. Marty rips out the phone book page and asks the guy behind the counter where XXX Riverside Drive is. Marty is no longer wearing the watch which he just had on seconds earlier. (00:37:55)
Revealing mistake: When Doc is using a remote control to drive the DeLorean, they show a close-up of the controller. The controller's power meter (the dial with a needle in the middle) shows no power - it's right over to the left. How's he driving with no battery? (00:20:15)
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.
Continuity mistake: When Doc points out that Einstein's watch is in sync with his, the LED display changes from being off in a wide shot to on in the closeup. (00:20:05)
Continuity mistake: When Marty McFly is being chased around the town square by Biff and his buddies in the black convertible, an extra set of lights appear under the headlights on the car (goes from a 1946 Ford to a '47/'48). (01:06:45)
Continuity mistake: After Einstein comes back Doc Brown is demonstrating to Marty how to set the time machine. He simply pushes the buttons on a key pad. To set it for July 4, 1776 he punches 3 buttons. To set it for December 25, 0000 he punches 6 buttons. To set it for November 5, 1955 he punches 12 buttons. Later, when Marty is resetting the time machine to go back 10 minutes early he punches 7 buttons (all not including the ENTER button on the keypad). (00:23:50)
Revealing mistake: When Marty is skateboarding and being chased by Biff's car, Marty's stunt double is noticeable because his wig is bulkier and darker coloured than Marty's real hair. He looks just like the Trololo guy from Youtube. (01:40:50 - 01:41:25)
Visible crew/equipment: When Marty arrives at the 1950's town and is about to be run over by a green car, the whole filming crew is reflected on its door. (00:35:40)
Continuity mistake: When George and Marty are talking outside the diner and George opens Marty's coke bottle for him, George's hair is all stringy and hanging down in his face. But when it cuts to another angle, it's neatly combed over to one side. (01:03:10)
Deliberate mistake: The 45's advertised as new releases on the record store sign actually came out at different times throughout 1955. A true selection of new releases from early November 1955 would have most likely included minor hit singles that 80's moviegoers wouldn't have recognized. The songs listed were some of the biggest hits of that year and were obviously chosen for their ability to help set the musical tone of the time. (00:34:30)
Continuity mistake: Marty's hairstyle changes when Jennifer kisses him on the town square bench. (00:10:45)
Revealing mistake: After Einstein's time travels, when both flames cross Marty and Doc's legs, they cast no shadow, giving the feeling that they are floating, thus giving away the blue screen effect. (00:22:01)
