The Beacon - S1-E26
Plot hole: Barrows introduces himself as "Dr. Dennis Barrows," and Teddy asks, "What's a doctor?" As the isolated villagers have never heard of doctors, Teddy would have no way to know that "Doctor" was a title/profession and not simply part of Barrows' name. He should have asked, "What kind of a name is Doctor?"
Smoking Gun - S1-E2
Plot hole: Lori managed to get to the bunker through the elevator because the modern board was still replaced by the antique one. But that implies that she was able to call the elevator as normal. And if people can just call the elevator back but the normal control board has been replaced, then they wouldn't be able to use the elevator as normal, creating quite a problem in a huge hotel. Sydney earlier was not able to switch the board back to the normal one since she went out from a (mysterious?) exit/entrance, so this situation makes no sense.
My Late Lamented Friend and Partner - S1-E1
Plot hole: When Jeff and Marty are parked, waiting for Sorrenson to exit the building opposite, Jeff says he should call the police. But he immediately follows Sorrenson and has no time to do so. Later, they arrive even though not called.
Plot hole: I believe in the very first episode, during the flashback when Mick remembers rescuing Beth and killing Coraline, we see him stab her with a wooden stake, which is supposed to paralyze a vampire, as said in the "Dr. Feel Good" episode. However when Mick looks back with Beth in his arms, Coraline suddenly gets up and watches him leave while burning to "death." This is simply not possible; in the "Dr. Feel Good" episode, Mick could not release the stake himself and asked Beth to do it. This also happened in the episode when Josef was staked by the hit man that was hired to kill him, (in the episode where we meet the woman, Sarah I believe, that he accidentally put into a coma after attempting to turn her). Again, Josef was unable to remove the stake himself and Mick had to do it for him, so there is absolutely no way Coraline would be watching Mick and Beth leave; she would still be on the ground possibly burning to death.
Plot hole: Cleo's photo album contains photos of her and Lewis from past episodes ("Love Potion", "Doctor Danger" and "Hocus Pocus"). It's impossible that their photos could have been taken because they were alone in all of them. (00:03:07)
Plot hole: We learn the rangers were pre-selected to join the team and were in waiting until called to duty, but the yellow rangers sister just passed the legacy onto Emily, who was only a child.
Plot hole: During "the changes" people fear machinery, but the woman who pulls back her curtains to watch Nicky and the sikhs go past is wearing a watch.
Plot hole: WARNING SPOILER AHEAD. The alien impersonating Skokes changed the ship's destination to Earth. This is impossible to have been done, as the first order the captain gave was to lock the course in and "Skokes" admits his security clearance was removed after his rescue from his prison. It also couldn't have been done by another alien spy, as no other survivors beyond the 4 (2 human and 2 aliens) were found and the only other alien spy was unconscious, so he couldn't have helped out in any way.
Plot hole: Loki states while on trial that The Avengers should be on trial for traveling through time to change the timeline. How did he know they came back through time?
Suggested correction: He recognized that there were two Tony Starks in the lobby by the smell of their colognes, and combined with all the other unusual shenanigans going on, he correctly deduced the Avengers travelled through time, though he incorrectly thought it was to prevent his ascendancy.
How exactly do you distinguish the smell of cologne as belonging to two separate people? But besides that, it's pretty wild to jump to a conclusion about time travel when it could be that someone else happens to be wearing Axe.
I'm sure he simply recognized his voice.
Plot hole: The powerful 'amulet of protection' makes the bullets strike the shooters instead of John. Clearly it works not just against magic and other ethereal threats, but also against physical attacks. So why does he almost get knocked over by a car? True, he isn't seriously injured, but he was thrown to the ground. The amulet should have pulverised that car or bounced it at least two blocks away.
Into the Mouth of Evil - S2-E23
Plot hole: While fleeing the guru's disciples through a narrow side street, Jackie gets cut off by the van driven by Dr. Jamba and associates, stun-sprayed in the face, and then loaded into the van. But with three brutish-looking guys being so close to their quarry, the real crooks can take the time for dragging Jackie around to the back door instead of loading him through the side doors?
The Feminum Mystique: Part 1 - S1-E5
Plot hole: If her younger sister Drusilla is sent from Paradise Island to retrieve Diana, how did she get to Washington DC or wherever, she had no way of knowing where her older sister would be.
Plot hole: The way slipstream works is wildly inconsistent across the show. Sometimes, they have to travel a significant distance to find the nearest slip point, and other times, when it's required by the plot, there's a slip point conveniently right next to the ship.
Suggested correction: How is this a mistake? Unless the points are evenly distributed and all close to each other, they are going to be different distances away.
Plot hole: During Ryder's report, as Bruce and company watch it on TV, the camera suddenly zooms in on Joker standing on a catwalk above Ryder, and none of the crew, especially not the camera man who caught the villain, makes a comment about this. They may have thought the Joker (or rather an impersonator) was perhaps a surprise gag in the show, but since this is supposed to be a serious documentary report, it is still strange that they wouldn't point it out.