Plot hole: The alien-possessed Mason steals Captain Lauritzen's fingerprints by pressing his fingertips to the captain's and "heat transferring" the prints. Big problems here: those prints would now be backwards and for the wrong hand. But when the computer later reads the prints, it fails to notice this and passes him through security as "Identity Correct." (00:23:30)
Video Mania - S3-E6
Plot hole: The plot for this episode is that Mark reluctantly tries out video games for the first time and soon becomes addicted to them. However, the season 1 episode "All in the Family" showed him to already be an avid gamer.
Career Fever - S4-E9
Plot hole: Peter thinks he has a fatal disease. The parents realise two pages stuck together and he went from page 95 to 98 mistakenly. However, Mike first read about the actual fatal disease info on page 97, and then Carol read about what Peter actually had on page 96 (poison ivy). If Peter read only 95 and 98, there would be no way of Peter to know his disease was fatal since that was printed on page 97.
The Wedding - S5-E11
Plot hole: In the episode "There Goes the Bride," Haji warns Jeannie that she will lose her powers if she marries Tony. Yet, she marries him in this episode and does not lose her powers.
Plot hole: In the episode where the Sliders go to the world where Quinn sees himself as a child attending his father's funeral. Quinn helps his young self deal with bullies. Quinn repeatedly mentions is was all happening the way it did on Earth Prime. The flaw here is that in the Series Premier episode, they showed a picture of Quinn, his mom and dad. Quinn was a teenager in that picture, not a kid. Therefore the events in the alternate world they were visiting could not be happening the exact same way. The man in the picture is the same man shown as his father in the other worlds so it cannot be a "stepfather" that his mom remarried.
The Robbery - S4-E4
Plot hole: Towards the end, Jake (Shirley's boyfriend), hangs the girls on a coat rack by the hoods of their coats. They try a few comical ways of trying to escape, when they could have simply unbuttoned their coats and slip away.
The Inspired - S9-E2
Plot hole: At the beginning of the episode, PD let the suspect go (twin 1) because they accidentally arrested him for the crimes that his twin brother (twin 2) committed. Hotchner still wants to question twin 1, but a lawyer threatens Hotchner to not go near the wrongfully accused twin 1. However, in the previous episode, FBI and cops pursued twin 1 and twin 1 didn't pull over. It would be legal for twin 1 to be detained on a reckless driving or eluding the police charge.
In Too Deep - S5-E8
Plot hole: Carter is apparently just learning about Feynman's Day, which Allison explains as "Eureka's version of April Fool's Day." It's highly improbable that Carter could have lived in Eureka for five years and still be oblivious of this, especially given all of the hijinks that happen.
Plot hole: The pictures James took were developed from his camera into photos even though he was arrested while taking those. How did they get developed? James' father didn't approve and his mother said she had found that stack of photos after the police searched his room. (00:26:30 - 00:30:00)
Plot hole: Every time the nanos stop absorbing electricity (for whatever reason), street lights, radios, everything 'on the grid' immediately starts to come back on. No re-building infrastructure, no restarting turbines, etc., even 15 year old streetlights lying on the ground, in the middle of nowhere.
Plot hole: The Triforce of Wisdom is kept in Link's room up in a tower. It does seem logical to keep it with Hyrule's greatest hero to keep safe, but that's all you ever see protecting it. Hyrule is a large kingdom, and the Triforce of Wisdom is a vital part of keeping their community safe. Yet the only one protecting it is Link. And he's not with it 24/7. The room is not very secure either and is breached all the time by Ganon's forces. A kingdom like this would have knights to post all around the tower and be in Link's room when he's away. But nope, not here. (00:01:10)
Plot hole: How do they travel all over so quickly? Why does it take the same amount of time to travel from one continent as it does city to city? Someone in Paris talks to another in Zambia and bam, they're together all of a sudden.
Plot hole: The show starts with the Jupiter crashing into the planet... also the other Jupiter seems to have had problems landing on the unnamed planet... why? The Jupiters were fully capable of flying around the planet as we saw it in other moments. None of them were attacked by the robot, they are not escape pods. So why crash land into the planet? Also why get out of the ship just to be stranded on an icy hellhole? The space ship is waterproof, as we saw in another episode. So why get out just to have one person go in again and get trapped on ice? And that's just the tips of the iceberg, pun intended.
Plot hole: In season five, the show depicts the aftermath of an Electoral College tie. The procedure in this case should be the House holding subsequent ballots until a president is elected. On the show, however, Tom James convinces the Speaker of the House to hold one ballot, and then not vote again. James' plan is to win the Senate vote for VP, then act as president for four years before being elected to two full terms as actual president. James is outmaneuvered and his rival Montez is elected VP, and subsequently acts as president for the remainder of the series. After season 5, the show makes no mention of the House ever taking up a vote for president again, and the show simply treats Montez as the actual president. A Speaker of the House blocking the election of a new president would likely cause a political uprising from supports of both candidates, and both candidates would rightly take to the airwaves to demand a new vote. The idea of a power-hungry politician such as Selina, who uses every trick in the book to promote herself and elevate her own power, putting up no fight is just bizarre.
Here There Be Monsters - S1-E10
Plot hole: The female police officer has a theory that Johnny was the Strangler in the case the papers claimed he helped solve but this hardly makes sense. If she was researching him as was seen in the episode, surely it would have said something about Johnny being in a coma during the bulk of the murders since the story was about Johnny.
Another Mother - September 30, 1981 - S2-E13
Plot hole: Sam wallops both kidnappers and rescues the son. They then leave the two child molesters unconscious beside their van. No one calls the police or has them arrested, so they're free to kidnap another kid. Sam doesn't leap until after an epilogue in which the loose ends are supposed to be resolved - but this question is left unanswered. It's not excused by a "just because we didn't see it happen doesn't mean it didn't" defense. The viewers shouldn't be left with a dangling plot hole, and one line could have cured this one.
Plot hole: In episode 1-7: "Unraveling," Christina and Jesse get on a bus to New Haven, first thing in the morning. Christina left the Kramers's house before breakfast. Then, they ride on the bus all day until getting trapped in a terrible storm in the dark of night. But New Haven, CT, is less than a seven hour bus ride from the Jersey shore, so anything that happened to them on the way there should have been in full daylight.
