Plot hole: At the very end of series two, there was a shootout during an armed robbery. WPC Granger somehow had access to a firearm. Surely the fact of her uniform rank would not have allowed this.
Plot hole: Kate in the Batcave says with absolute certainty "Alice doesn't know that Bruce Wayne is Batman. Whoever stole the gun, knew that Bruce had to have the suit to test it on." Both statements are leaps in logic with no foundation. Alice knows that Kate is Batwoman, and that Bruce's office is her center of operation (she even shines a bat-signal there!). It would be perfectly logical to assume that she made the connection. The testing bit is simply a non-sequitur; plenty of weapons can be made and tested on armor which fits the specifications, real or inferred, of a particular target, without being in possession of the item as a whole. (00:16:00)
Plot hole: Matlock figures out that The Professor wouldn't have been able to see the security guard from 50 yards without glasses, and that's what tips him off about The Conspiracy: the guard testifying that the man wasn't wearing any. However, when we see the scene happen at the beginning of the episode, the person posing as Prof. Erskine Tate is, in fact, wearing glasses. (00:04:15 - 00:22:15)
Plot hole: When Beverly is killed the killer shuts off the main power switch which would have turned all the lights off in the house, not just those in the bathroom. (01:31:00)
The Daughters of Jerusalem - S2-E6
Plot hole: Dinah Fortescue's fingerprints are supposed to be on a teacup but she's wearing gloves in the flashback. So how did they get there? (00:24:35 - 00:33:34)
Plot hole: When Two-Face and his men have broken into the new D.A.'s office to find dirt on Rupert Thorne, one of his men finds a file detailing Thorne's record of Swiss bank accounts, money laundering, blackmail and payoffs that Two-Face tried for years to subpoena when he was D.A. When Thorne finds out that Two-Face has the file, he states that he will be ruined if Two-Face gives the file to the police. If Two-Face tried unsuccessfully for years to subpoena the file, then in all likelihood that means Thorne paid off the right people to prevent the subpoena from happening, so Two-Face giving the file to the police shouldn't be a problem for him. Additionally, if giving the file to the police would be all that it would take to bring Thorne down, then the new D.A. could have already done so. If the new D.A. was also paid off by Thorne, then it wouldn't make sense for Thorne to allow the D.A. to keep the file since they could easily lose the file or even double-cross Thorne. (00:10:45 - 00:14:20)
The Amazing Psych-Man & Tap Man, Issue No. 2 - S6-E4
Plot hole: The flashback involves Young Shawn and Gus getting ready to go to a comic book convention, Shawn in costume, with his father's consent. This contradicts the flashback in "Shawn Vs The Red Phantom," where Henry won't allow Young Shawn to even read comic books or play superhero with a towel around his neck.
Over My Head - S3-E4
Plot hole: Daphne was able to hurt Duke because his name appears on her cell when he called, but names only show up on a cell phone if the person's number and name are programed into the phone, and Duke has already said he doesn't know her.
The Monsters are Due on Maple Street - S1-E22
Plot hole: The street sign in the beginning is all wrong: it faces the camera rather than the street where the story takes place. In a typical American city, street signs are almost always placed in the direction of the street they are indicating, so drivers on the other street in the intersection know what they are turning onto or passing. In other words, the story is not set on Maple Street! Maple Street is the intersecting street at the end of the road the story is set on.
Are You...? - S7-E1
Plot hole: It's out of character and against his code for Dexter to kill Viktor at the airport. Airports have security cameras everywhere (you can see one on the ceiling when he is wheeling Viktor into the unclaimed baggage storage), and using the unclaimed baggage storage as the kill room is equally unwise, because any airport employee could walk in at anytime and catch him red-handed. Dexter was caught murdering Travis Marshall by Deb just hours before, so if anything, he should be even more cautious.
Plot hole: The captain's wife tells him that she's taking his daughter with her, not giving him a chance to even say goodbye. During the episode it turns out that she's angry because he missed lunch with them, and when the Metal Wu texts the boss, it also turns out that all this just happens at 1:11 AM! It does not make much sense: she waited over 12 hours to complain to her husband, and she's driving her kid in the middle of the night.
When the Guns Come Out - S3-E6
Plot hole: Raylan has a hunch that Winona took the money again from the evidence room, so checks the locker, finds the empty box, and assumes she stole it. When they returned the money in the previous season, he said "Put it back anywhere except for where you found it", so as to make it easier for someone to assume it had been misplaced, rather than lost. So the locker being empty is hardly a smoking gun for him to assume Winona's taken the cash.
Thank Heaven for Little Girls and Big Ones Too - S1-E4
Plot hole: "Three Tahitians", one of the masterpieces from one of the most famous post-impressionist painters in the world, is authenticated by an ordinary school teacher. Because that's the person for this multimillionaire job, obviously. (00:25:20)
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: Amy lets Scully place the watch in the break-room, but how could she have known that after Captain Holt steals the crown out of the locker, he would go there? And not, for example, go back through the window he came from.
Farewell My Beloved Witch - S1-E3
Plot hole: Lupin was captured by chance, and he did not plan for that, nor he seemed to have previous knowledge of Stern's appearance, but he escapes regardless using a Mission Impossible-like perfect mask of him. He also somehow kept his own blazer, tie and shoes underneath the uniform and boots he stole and wore. (00:16:00)
A Deadly Net - S2-E2
Plot hole: S2E2 A Deadly Net Midway through the episode, Sylvia and others in the cast bid people goodnight, offer after-dinner drinks, but the sun is shining brightly and continues to do so for quite a period of time as events continue to unfold.
The Countess - S1-E4
Plot hole: Rockford and Carl Brego are punching and kicking each other on the beach. Someone shoots him down with a rifle. The INSTANT Rockford goes to check out if he's still breathing, two people randomly happen to walk on him popping over from behind a rock as they were having a super casual and amused chat, but see Rockford by the shirtless brute and make a horrified face. Later in the episode the two identify Rockford and say that it looked like the two were fighting. Their facial expressions at the time don't make sense as depicted. Even if we assume that they did not see anything at all and they played it up/filled the blanks in their mind later, the two are not deaf and yet they were not perturbed or curious in the slightest after the loud bang of a gunshot. The way the scene was shot, the only thing tipping them off about anything was seeing Rockford over the corpse (which had barely a small dot of blood visible at the time and would hardly tip anyone off at first sight). (00:18:45)
Plot hole: Episode 1: All passengers on cruise ships have a passenger card with their name and cabin number imprinted. They are not just identical key cards like in hotels.