Corrected entry: In the first scene from 1955, November 6th, where Marty watches the mix of people in Courthouse Square, there is a shot where a boy in mustard yellow pants, standing next to a man, under a tall tree, is "bouncing" down the sidewalk on a pair of spring-laden shoes. These shoes were called "rocket shoes", and were not invented until the late fifties/early sixties, not 1955.
Corrected entry: On the DVD version, in the scene where Doc gets shot and then later reveals to Marty that he was wearing a bullet proof vest. A vest does not work in the way shown in the movie. It doesn't repel bullets (as shown in the "impact points" in the vest he displays), it absorbs them. Read how a vest works from howstuffworks dot com and you'll see what I mean. In addition, it looks like he is wearing only a Threat Level 2a class vest. An AK47 or similar weapon with a 7.62mm round would go clean through the vest, through Doc, and out the other side thus killing him and ending the story. The only style of vest that can withstand that sort of impact is a Threat Level 3 class vest (the style that specialized units in the military wear). This style is very bulky and is extremely difficult to conceal like Doc did. In addition, it has a ceramic plate in it which would have shattered upon the first impact and failed to protect against multiple impacts from that kind of weapon, and definitely not show "impact points" of twisted metal.
Corrected entry: When Marty escapes the Libyans at the Twin Pines Mall, hits 88mph and ends up in Old Man Peabody's barn, driving in through a large opening in the barn before crashing. However, the cut to the inside of the barn shows no form of entry other than the closed doors the family are entering. In addition the inside of the barn is very small compared to the outside view. (00:30:10 - 00:31:55)
Corrected entry: The DeLorean has 'Good Year' tyres - this is a deliberate mistake to create an in joke, as the brand is actually 'Goodyear'.
Corrected entry: In the speaker explosion scene at the beginning of the film, a horizontal safety line can be seen attached to the waist of the stunt person as he is knocked backwards.
Corrected entry: When Marty first enters Lou's cafe in 1955, Lou is visibly angry at Marty just because he won't order something right away. However, he doesn't seem to care that one of his paying customers, George McFly, is being harassed by Biff and his gang and told never to come in there again. You would think Lou would tell Biff and Co. to knock it off or else be asked to leave.