Continuity mistake: When Marty is trying to escape from the van he turns the time circuits on. However, the time circuits were already on - you can see them illuminated when he first puts the car in gear. (00:28:45)
Continuity mistake: In 1955, when Doctor Brown is watching the video of himself, he sees himself saying that the Libyans are coming. You can hear a significant pause between "They found me" and "I don't know how but they found me." But in the beginning of the film he says the entire phrase without any pauses. (00:28:45 - 01:08:10)
Continuity mistake: When the Libyan terrorists show up in the VW bus, there is no license plate at the front, but in some of the following shots during the scene a blue license plate is affixed to the front bumper. (00:28:55)
Continuity mistake: When Marty is being chased by the Libyans, a few times it cuts away to show the instrumentation in the car. The first time the odometer reads 33064.2 and the trip counter says 88.8; the second time it's goes back a little to 33061.8 and 86.4. A few seconds later we see it as he turns the corner, and it goes down again from 33,061.8 to 32,994.4, the trip counter has gone from 86.4 to 19. In fact it's a completely different set of instrumentation - the bottom of the needle's angled in some shots and flat in others. (00:29:20)
Continuity mistake: At the Twin Pines mall during the chase scene with the Libyans, there is one shot where you get a great look at the driver as he's trying to start the engine. Later on you get another look at the driver as the van is moving and it's a totally different person. (00:29:52)
Continuity mistake: In the chase scene with Marty and the Libyans, Marty is driving away from them. He changes into second gear but in the next shot he shifts into second gear again without changing back. (00:30:15 - 00:31:10)
Continuity mistake: While being chased by the terrorists Marty passes the J C Penny's store, drives a little farther and passes it again. Just before the Libyans aim their rocket at Marty, their van changes from about 100 yards from the store to right in front of it in less than a second. (00:30:25)
Continuity mistake: When Marty arrives in 1955, he lands on Peabody's farm and rams through the pine tree he then hits a scarecrow which flies over the top of his car. Then as they show it from the inside the scarecrow slams into the windshield - but how can it slam into his windshield if it is already over the car? (00:31:30)
Continuity mistake: As the Peabodys try to determine what crashed into their barn, the DeLorean's left indicator flashes throughout. When the family is onscreen, the barn's interior goes completely dark between flashes - whereas there should be illumination from the headlights as well. Compared to a later point in time where Marty opens the barn door to get shot at, it's not hard to notice how bright the headlights are. (00:31:50)
Continuity mistake: When Marty gets out of the DeLorean to look at the "Lyons Estates" markers it is supposed to be a little past sunrise. The shadows should be very long, but all of the shadows are small. The scene must have been shot much closer to noon. (00:32:40)
Continuity mistake: After Old Man Peabody fires his rifle at Marty, it changes position between shots. Initially the rifle is trained on the barn doors, but when the DeLorean busts out a moment later he's got it aimed at the ground instead. (00:33:05)
Continuity mistake: When Marty leaves the Peabody farm and turns onto the paved road, it has solid white lines marking the sides of the road. A few seconds later, Marty is shown driving down a road without white lines on the sides, even though he's apparently only driven a short distance down the road. (00:33:30)
Continuity mistake: After escaping from the Peabodys, Marty stops the car in the middle of the road and exits with his hair all messed up. A frame later it's brushed. (00:33:57)
Continuity mistake: When Marty sees the Lyon Estate works there's a mild breeze blowing. Just a frame later, from a new angle, there's a very strong wind. (00:34:18)
Continuity mistake: When Marty arrives in 1955, he puts the DeLorean behind the sign, and walks into Hill Valley. When Marty and the 1955 Doc come back later, the DeLorean is facing the other way round to what it was at the beginning (you can tell because at the start Marty pushes the BACK of the DeLorean AWAY from the Lyon's Estates billboard, but when they come later, the FRONT is facing TOWARDS the billboard). (00:35:05 - 00:51:15)
Continuity mistake: When Marty is in 1955, he is in shock and walking on the pavement when a car comes by. In the first shot when it comes towards him it has two speakers, on the second shot when it's moving away, it only has one. In the second shot of the car with only one speaker, the A-frame sign is also turned the other way. (00:35:15)
Continuity mistake: Cafe 1955, when Marty enters for the first time. The arrangement of the coats on the rack to the right-hand side of the cafe doors changes upon Marty's initial entrance and returning to the counter after using the phone booth. (00:35:50 - 00:36:40)
Continuity mistake: As Marty takes in his surroundings at the 1955 town square, he pauses for a few seconds to glance at the Roy's Records storefront. In that short span of time, the cloud cover changes entirely. (00:35:55)
Continuity mistake: In the cafe in 1955 Marty goes into the phone booth to look up Doc's name in the phone book. When he finds it the name is on the left hand page, but when he tears it out of the book he tears out the right hand page. One could say he turned the page to tear it right-handed, however when he is asking the waiter if he knew where the address was, he is reading the address on the same side he tore out - check the tears on the edge. (00:36:30)
Continuity mistake: When Marty enters Lou's Cafe for the first time, check a group of people gathered outside next to the doors who say goodbye and leave the place. A shot later, they're all back together, talking. (00:37:46)
