Corrected entry: If everything that happens in the past, determines what happens in the future,and there in between, then wouldn't it make more sense for the picture of the family, when it starts to come back, to have them dressed differently? Such is the case when they are in the new family scene, when they come back.
Corrected entry: When Doc is on the clock tower attempting to reconnect the cable, he pulls it and disconnects the other end (indicating the cable has just enough slack to touch the ground from point A and then be inches short of point B). Doc then connects the cable and then ties the cable around the clock hands. The other end of the cable is only held by a fallen branch, if he were to really propel down the cable, he would have gone completely vertical down. When he lands, the cable would have been shorter due to him tying it to the clock hands. Also a shock of 1.21 gigawatts would have landed him in the hospital if not the funeral home.
Corrected entry: The license plate of the time machine is spinning on the road in the middle of the fire tracks - further down the track than where Doc and Marty stand. But the car (and therefore the license plate) was never there. It had already 'jumped'. Otherwise the license plate had to pass through Marty.
Corrected entry: At the very end, Marty tells Doc that he'll have to back up as they don't have enough roads to get up to 88mph. The next shot we see shows the avenue stretching off at least a mile into the distance, with plenty of road to reach that speed. Since the DeLorean was able to achieve 88mph in a parking lot, it should be fairly obvious to Marty that there is no issue with them not having enough road.
Corrected entry: When Marty pulls out of the barn and runs over the pine tree, it's pitch black outside (the sun hasn't risen yet). The subsequent shot shows Marty driving his car and telling himself it's just a dream...now it's complete daylight. Is the Twin Pines Mall/Twin Pines Ranch so far away from Hill Valley that it takes a sunrise's-worth of time to DRIVE from one to the other? Doubtful, since it only took Marty about 15 minutes to skateboard there from his house (and pick up Doc's camcorder along the way).
Corrected entry: Towards the end of the movie when Marty is driving down the street in 1955 to go back to 1985, Doc is trying to get the electricity cables back together for the lightning needed to send Marty back to the future. Doc then slides down the cable to connect the cable to the other one over the street. As he's about to connect the cable, the lightning strikes. He then has at least half a second to connect the cable and he does. But the lightning takes at least two seconds to get from the tower to the car. This is way to slow for electricity. Electricity can move around the world four times in a second.
Corrected entry: When Marty goes back to Nov. 5, 1955, the time is set for 8:30 AM. When he arrives he walks around a bit in amazement and then heads towards Hill Valley. The sign he passes says "Hill Valley 2 miles." When he gets there, look at the clock tower, the time is about 8:30 (give or take). He couldn't have run the two miles in under a minute even without hiding the DeLorean.
Corrected entry: In the beginning, when Doc awakens Marty in the beginning he tells him to meet him at "Lone Pine Mall" (the altered name of the mall after the movie) but when Marty arrives at the mall the sign still reads "Twin Pines Mall". How come Doc is referencing the new name that hasn't changed yet? And this scene occurred just before any time traveling took place so it's definitely not a paradox (most likely a script error).
Corrected entry: American police may be so lackadaisical that they don't attend the scene of a car racing noisily around a car park, followed by a loud crash of a van hitting a shed, but I find it hard to believe that they don't investigate continuous machine gun fire from the same area. There are occupied building all around the car park, and there is plenty of time for them to turn up.
Corrected entry: When Marty is being chased by the terrorists, he disappears through time, and the terrorists crash their van into the photo-booth, which presumably stops them dead in their tracks. But really, how would trashing that small booth make the bad guys irrelevant from that point onward? They weren't killed. So realistically they'd all get out of their crashed van and proceed to wreak more havoc. Yet in the time it takes Marty & Doc Brown to gather up all their stuff and drive away in Doc's van, the terrorists don't lift a finger to chastise them or confiscate the remaining plutonium.
Corrected entry: When back in 1985 Marty's mom asks if this is the night for the big date, Marty answers "How can I go to the lake when the car is wrecked?" His family reacts by going out and checking George's BMW. Seconds later we see that Marty has his own truck - shouldn't they have been checking on that instead? And if it's because he talks about the car (i.e. the BMW) instead of the truck, they should have wondered why he was going to take his fathers BMW up to the lake instead of his truck.
Corrected entry: During the first Lou's cafe scene in 1955, Marty asks for a Tab, then a Pepsi-Free, then "something without any sugar in it." Pepsi-Free was "free" of caffeine, not sugar (Diet Pepsi was "free" of sugar). Marty knows this because he is seen with both Diet Pepsi and Diet Pepsi-Free in 1985. Of course, had Marty asked for Diet Pepsi in 1955, Lou would not have been able to say "Hey, you want a Pepsi, pal, you're gonna pay for it." (00:38:30)