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)
Revealing mistake: When Marty is being chased by the terrorists, when he makes the 2nd turn, if you look closely at Marty it is obvious that it is not Michael J. Fox behind the DeLorean windshield, rather it's a stunt driver resembling the original Marty, Eric Stoltz, who was replaced early in filming. (00:30:45)
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)
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)
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)
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)
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)
Other mistake: The car that almost runs Marty over has the vehicle registration plate of 6S 48405. Later on, when Marty is hit by Sam, Sam's car has the same plate. (00:35:49 - 00:42:02)
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)
Revealing mistake: Marty finds Doc's name in the phone book; when he sees the name, then runs his fingernail over to the phone number. Look closely at the phone book; it has several creases across the same place where Michael J. Fox ran his fingernail from previous takes. (00:36:15)
