Seeing as Marty changed his future, shouldn't the photo of himself, his brother and sister be different? [Not really. The events of that day, leading up to the picture being taken, could have been the same.]

The rods of plutonium are transparent red, whereas real plutonium is a silvery metal. [More than likely they would have used a dilute plutonium compound (According to Wikipedia the red colour suggests Plutonium (IV) chloride, rather than pure plutonium metal, which is highly dangerous to handle outside controlled conditions, as it emits enough gamma radiation that would kill Marty and Doc within seconds.]

When Marty is recovering from being hit by the car, his mom continually refers to him as Calvin. When Marty asks why, she responds "Well thats your name isn't it? Calvin Klein. It's written all over your underwear." But when Marty puts his pants on, we see his purple underwear and there is nothing written on them. [The writing is on the waistband of the underwear which is covered by Marty's shirt. If you watch in slow-mo Marty lifts part of his shirt for a split second and you can see something written on them.]

Following the mistake about the menu design in the cafeteria, look at the background. The sun has moved a lot. Look trough the window and you'll notice the shadows were a second before was sunny. [The shadows can easily be explained by passing clouds.]

When Marty is driving the time machine trying to escape the Libyans, he shifts gears to get up to the speed he wants. Yet when Doc puts Einstein in the time machine he never shifts gears at all and he power brakes, which can only be done with an automatic, there isn't even a device on the remote control to shift. [You can power shift with a standard transmission, it's just not as easy since you need to heel and toe the accelerator and/or clutch. Most Deloreans were manual transmissions. We don't know how Doc built the remote control, so we don't know if he built into it a means of shifting to a preset pattern, or if he had something like a pushbutton to shift the car that we don't see on the remote control.]

When Doc shows both his watch and Einstein's watch, the time is 1:19 a.m. From that time, to the time Einstein goes into the future which is 1:20 a.m, is really 1 minute 45 seconds. [This is not inconsistent. If Einstein left at, say, 1:19:10, and arrives back at 1:20:55, this would be a minute and forty-five seconds, and the watches would be consistent.]

In the opening scene where Marty plugs his guitar into the gigantic amplifier, there is no feedback - if he was standing that close, at that volume, with that amount of overdrive, there would be some ridiculously loud feedback almost instantaneously. The pickups on an electric guitar will feedback the output from a speaker just as easily as a microphone does. [Given that Doc has just invented a time machine, the idea that he could invent an amp that doesn't suffer from feedback isn't so far fetched.]

When Doc and Marty go to Hill Valley High School in 1955 (to look for his parents), the bell rings and everyone in the corridors leaves and goes into several classrooms. About 2 or 3 minutes later, when Marty and Doc are discussing how to get his parents together, the bell rings again and everyone in the classrooms comes back out to the corridors. It can't be because of registration because when Doc and Marty arrive, the bell is heard ringing and people are in the corridors suggesting that either registration or a lesson had just finished. [Some schools have "homeroom" which is only about 4 or 5 minutes long.]

Einstein, Dr.Emmett's dog is the first to travel in the time machine. He travels one minute into the future during which he ceased to exist in the current time only to reappear one minute later. According to this it hence would be impossible for the Doc, Marty and his girlfriend Lorraine to travel into the future and see their futures as they would have ceased to exist as of when they left the current time until they reappear in the time they set hence impossible to have continued their normal course of life and exist in the future. [It's a time travel movie. These things happen. The fact that Marty and Jen see themselves in the future is merely proof that they were going to make it back okay in that timeline.]

The morning after Marty has returned from 1955, there's a shot of Biff waxing George's car. Behind Biff we see his "Biff's Auto" yellow truck, however when Marty goes to the garage to see his new pickup truck, Biff's yellow truck has suddenly disappeared. He couldn't have suddenly left - he'd just been given a severe talking-to about not doing the second coat of wax yet. [We know Biff didn't leave because he brought in the box of George McFly's book "A Match Made In Space", but it is possible that Biff could've moved the truck out of the driveway. After being giving a talking to about not doing a second coat of wax he probably doesn't want to block up his employer's driveway.]

After the Libyans have shot Doc Brown, Marty screams "Bastarddddddd." When we cut to Marty after he has said it, his lips aren't moving, yet the "rddddd..." can still be heard. [It only continues for a fraction of a second after, and that can be attributed to echo.]

In the very beginning of the film there is a clock with a cat on it. This is the same clock used in "Honey, I Shrunk The Kids," which is another Robert Zemeckis film. [Robert Zemeckis has no connection with "Honey, I shrunk the Kids" at all.]

How does Doc know that lightning will hit the clock tower at precisely 10:04:00? Since the minute hand only advances once a minute, it's possible that the clock was struck anytime between 10:04:00 and 10:04:59. [Actually the gears inside the clock tower would tell you how many seconds had passed, so assuming that the story about the clock tower was researched correctly they would be certain that the bolt hit at 10:04 precisely.]

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. [Doc is a brilliant scientist as well as an inventor. He had the time and the ability to invent his own special material that works like no other material known to man. If he can invent a time machine, I'm sure a bulletproof material would be easy for him.]

At the very beginning of the film we see the machine Doc has invented to feed his dog. It takes a can of dog food and positions it under a can opener, and the lid is held by a magnet after it is cut off. The machine then tips the contents of the can into a bowl which holds three or four days worth of dog food, indicating that nobody has been around for a while. So, who has been removing the lids from the magnetic holder? [The previous lid gets knocked off when a new can is picked up.]

California license plates only allow for 7 letters. But the Delorean has a California plate with 8 letters (OUTATIME). [Actually, the "OUTATIME" plate is just a vanity plate (obviously added by Doc). The DeLorean has a real, registered California plate on its opposite end: 3CZV657.]

When Marty goes to see Doc in 1955 we see Einstein as a puppy. This would mean that in 1985 Einstein would be 30 years old. Though not completely impossible (the oldest dog in the world ever was 29) it is highly unlikely. [The dog in 1955 is a different dog. The Doc even calls it by a different name after another famous scientist, Copernicus.]

When Marty is in the Delorean ready to go back to 1985, he gets upset that Doc Brown tore up the letter and that he didn't have enough time to warn Doc about his future death. When Marty realizes that he can use the Delorean to go back early and warn Doc Brown of 1985 that he will be killed, Marty says,"Ten minutes oughta do it." Marty actually gives himself eleven minutes. [So he can't do math in his head in a few seconds. Character mistake.]

In the escape from the Libyan chasers, watch the ending of the chase. Marty already pushed the car to 90 on the analog speedometer, but the digital barely even made the jump to 88. [Analogue speedometers are not, as a rule, particularly accurate, hence Doc's choice to put in a digital version. It's not unreasonable that the two could differ in their reading by several miles per hour.]

At the point where Marty shows the Doc the video camera from the future and hooks it up, the recording plays. Then Marty fast-forwards the video. While fast-forwarding, when the Doc lifts the camera up and turns it around to admire the technology, the blue wire falls off the video camera. When resuming play after a few seconds, the video turns out to be just fine, though without the cable, the image/sound or electricity should have been interrupted. [That's the cable to the main electricity supply, which also works as a battery charger. So as long as the battery on the camera is already charged, it will keep working.]