Plot hole: The whole problem with the teleporter occurs when fly DNA is mixed in with Seth Brundle's DNA, starting his transformation into the Brundlefly. Brundle is on a hiding to nothing from the word go, and the fly is irrelevant. Humans are a walking talking mass of foreign DNA - we are host to one trillion bacteria all of which has a complete complement of DNA, as do various tiny mites that live in our hair follicles and all sorts of single cell organisms in our gut. If the transporter serves to mix the DNA of all living creatures which are in the transporter pod at the time Brundle would turn into a half-man, half-bacteria. Incidentally, DNA from a bacteria, an amoeba or a hair follicle mite would be just as 'compatible' with human DNA as that from an insect. It's quite a simple chemical, really.
Visible crew/equipment: When the Kurgan is fighting Ramerez he hits the wall and stones fall on him. A crew member can be seen pushing the stones out. (00:56:35)
Other mistake: After they take off from California, Kirk gives a heading to Alaska. He then tells Sulu "full impulse power", and Sulu says "aye, ETA 12 minutes." Full impulse is 1/4 the speed of light. No way they would use speeds like that to go a few thousand miles.
Visible crew/equipment: When Newton is playing with the robot arm and the piano you can clearly see wires attached to the top of it controlled by the puppeteers.
Revealing mistake: When Ripley first burns the egg plants inside the nest, the Queen screams and moves her head. The steel rod used to hold the Queen's head to the rest of her body is easily visible.
Audio problem: A soda can that is supposed to be full hits the man. When the can hits the ground you can hear that it's empty.
Factual error: When Steve Martin dies with the mask on, the inflation bulbs (the little black bags that inflate and deflate) deflate completely. Actually they should INFLATE completely and stay that way. The gas is still on full blast and Steve is no longer inhaling (which would cause them to deflate). It was done only to emphasize Steve Martin's demise but it's factually incorrect.
Continuity mistake: In the battle scene at autobot city, Megatron orders Soundwave to jam the transmission that Blaster is sending to Optimus Prime. When Soundwave ejects Rumble, Frenzy, Ravage & Ratbat we see them flying through the air transforming simultaneously and and both Rumble & Frenzy are coloured the same (red & black) when Rumble is supposed to be purple. (00:15:08)
Factual error: When the first robot is trapped in the lift, the teenagers shoot the propane tanks on top of the lift in order to get them to catch fire and explode, killing the robot. However the teens are firing pistols or shotguns, and these do not contain incendiary ammunition, which is what is required to make the propane to catch fire.
Continuity mistake: In a matter of 15 seconds between David's ship exiting the hangar and shooting 20 miles upwards into space, shadows on the ground indicate very different positions of the sun. (00:51:05)
Continuity mistake: The film is supposed to take place in 1917, but several of the german soldiers our heroes encounter are armed with Bergman M18 sub-machineguns which didn't appear until a year later. To make things even worse all the guns comes with a magazine-type that didn't appear until the mid-thirties.
Revealing mistake: The "blower" on the yellow Firebird never runs. NO wonder he couldn't beat the Wraith. (00:44:10)
Revealing mistake: After the bounty hunter, who changes three times throughout the movie, changes into the Reverend, he is in front of someone else who is a stand-in for the real Reverend but is obviously not.
Other mistake: When they first get into space and Tish removes her helmet her left earring is free floating, which would be expected in zero gravity. But after this first shot, her earrings hang down as effected by gravity. Also all three of the girls hair hang down with gravity the whole time they are in space. (00:54:45 - 01:03:15)
Other mistake: How does Dola know that Sheeta's pigtails were shot off? They had been outside in their aircraft the whole time and once Dola got Sheeta in a tight hug, the situation doesn't call for any time for her to explain what happened.
Visible crew/equipment: When the Overlord is busy destroying the Diner, when he starts destroying stuff on the counter, you can see the small rods pop up that flip the saucers and glasses into the air. You can also see the compressed air they used, to aid with the effect.
Factual error: In an early scene, the high school science teacher produces a schematic diagram of the two nuclear bomb designs created by the Manhattan Project. He says, "Here are two designs based on plutonium." Actually, only the Fat Man bomb uses plutonium. The other, the Little Boy design, uses uranium.
Audio problem: When Chris and Cynthia are hiding in the little shed from the zombies, there was a scene where a zombie grabs Cynthia and pulls her outside the shed. As she is being pulled out she reaches out to Chris and screams "Brad, Brad" a few times. Brad was her boyfriend whom they killed a few scenes before. But she was with Chris and not Brad so she should have called for Chris instead of Brad.
Revealing mistake: At the end of the movie, the main creature has the head of a human. However, in a number of shots you can see the actor's neck showing how they made the head "appear" to be attached to this creature.
Revealing mistake: When the bully's held up by Sam wires can be faintly seen.
Suggested correction: Being as how the bacteria and mites and such were IN or ON Seth, the machine was able to organize those symbiotic relationships accordingly as teleporting one would teleport all. The fly was separate, not touching. The machine was not programmed to anticipate two separated entities and so combined them into one on the other side.
Phixius ★
We leave behind a vapour trail of bacteria and viruses (among other things) as we walk, in our breath and emanations from pores in our skin, and Brundle isn't trapping any in his clothes as he isn't wearing any. Brundle has an invisible cloud of DNA floating around him in that teleportation chamber and as far as the machine is concerned their DNA has exactly the same status as that of the fly.
We don't know enough about how the machine works to determine how it might differentiate different DNA types. Unexplained science means it's somehow able to do it. Willing suspension of disbelief for the win.
Apart from blatant continuity errors and examples of visible crew or equipment, you just invalidated every posting on this site.