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.
Plot hole: When Terry gets back to her computer, after escaping from the spies and cops, the time is after 3pm New York time. If Jack actually is in Russia or Eastern Europe, wouldn't he have already gone to, and been killed at, that 5pm meeting?
Plot hole: Sarah breaks a mirror in frustration by throwing something against it. Then she buries her face in her arms and sobs. It remains a mystery how she managed to cut her hand so bad that it needed to be fixed with five stitches, as she isn't even seen picking up the pieces. (00:59:15)
Plot hole: Doug begins to land on the air strip after his father has been moved. But note, the Hades bomb had not yet been dropped. If his dad had not been shot at that moment, one can assume that he would have finished his landing and been a complete sitting duck when he has to get out of the plane. What was he saving the Hades for at that point? It is only later when he actually drops the Hades that he barely has enough time to rescue his wounded dad.
Plot hole: After Leo and the clerk finish looking up the fingerprints on the computer, the other cop says that the dead girl was dating Roland. When asked about Roland's address, the other cop says that he can probably find it somewhere and leaves the room. Leo is sitting directly in front of the computer that just gave them someone else's address. (00:47:10)
Plot hole: At the end of the movie, snails collect on the apparatus on which Oliver and Oswald have set up a time-lapse camera to photograph their decaying bodies, eventually short-circuiting the camera and wrecking their experiment. As they had previously (01:34:18) set up similar apparatuses in the same area (Alba's country estate) photographing other decaying organisms, why didn't the snails collect on them? (Pleasant film, huh?) (01:52:45 - 01:53:50)
Plot hole: In the debrief in Viper's office following Maverick and Goose's first flight at Top Gun (in which they defeat Jester), Viper states that "Commander Heatherly lost sight of you and called no joy." However, during the actual flight scene, you never hear Jester call "no joy." I've always assumed that this part of the scene was accidentally left in the editing room.
Plot hole: Throughout the film, Mitchell's main reason for not contacting police is that his affair and his mistress' murder would become public, derailing his wife's election and thus destroying "the one thing she built for herself". Seems odd that part of his plan is to rig his own car with explosives (from his own company), give it to the lead bad guy, then blow him and the car up on a public bridge. Certainly not a 'character mistake' as the tone of the film's ending is that, somehow, he has won, when he's failed in spectacular fashion to keep it all quiet- and his wife's been drugged, beaten, raped, and her career is over, while he's going to jail for murder.
Plot hole: Near the end of the movie, when Packard is about to race the Turbo, he puts on a helmet. Where exactly did he keep this helmet? The '77 Corvette is a two-seater with very little storage space for the passengers. Oggie and Minty's helmets could have been in the back seats of their cars.
Plot hole: If the Bird-of-Prey went to warp speed right after the whales were beamed up the ship would have already been so far away from Earth it would have been on its way back towards the sun, yet minutes later the ship is shown leaving the Earth, still at warp speed.
Plot hole: Chelsea says that when her deceased father gave her one of his paintings (now missing), he wrote an inscription to her on the back. She says she cannot prove that he actually did this other than he noted it in his journal and she does not know where the journal is. However, when Chelsea's father presented the painting to her on her 8th birthday, there were at least 100 adults present at her party who witnessed him giving her the painting, writing the inscription, and signing his name on the back of the canvas which was displayed to the guests. Any number of these people could be contacted and corroborate her claim.
Plot hole: Kelly is a friend of Jason's from LA and they have been seeing each other since he transferred to Seattle (he mentions 'the other day' she saw something at the pet store). Basically the one passion in life Jason has, is karate. Her brother is the US karate champion, and yet Jason didn't know that or even that he was from Seattle. That's absurd on several levels, since it implies that he wouldn't know her last name (then how did they stay in touch?) and they never ever talked about anything personal, because it's fairly obvious it would come up really easily.