Plot hole: After stressing (as Waverly did earlier) that only a laser beam can activate the explosive crystals, LeGallows demonstrates the destructive power of one - using only sunlight. (00:37:15)
Plot hole: The Seaview's crew have a wild shootout aboard ship, and their bullets are seen to go all the way through a 6-inch-thick hatch door. Gee, you'd think that somewhere during their military training, somebody would have taught these guys why firing high velocity weapons on a submerged submarine is a really bad idea. (00:38:15)
Enter Batgirl, Exit Penguin - S3-E1
Plot hole: When he abducts Alfred, believing him to be a minister, Penguin suffers a peculiar memory lapse. He's encountered Alfred twice before in previous episodes, even kidnapped him once before (knowing full well that he was Bruce Wayne's butler). Yet here, he fails to recognize Alfred at all. (00:12:30)
The Mutation Situation - S2-E1
Plot hole: The Krang ship carrying the shipment of mutigen is small, about a scout class ship. And it is seen flying past April and only a little bit above the top of the lower buildings in the city. The turtles have time to fight for a bit allowing the ship to get quite far away from April and her father. Yet Mikey accidentally causes all the canisters of mutigen to fall out of a hole in the floor and most are seen falling directly straight down towards the street, the ship being only about 5 to 8 stories above the ground. Yet somehow when it cuts to April seeing this, suddenly the sky is full of and raining canisters all over the city. And if cuts to her face even showing them raining down behind her. Which makes no sense because of how low the ship was, the canisters falling directly straight down in a tight cluster, and the ship having passed April a while back.
Plot hole: When the DigiDestined return to the real world, Izzy states that only a few minutes have passed by despite the weeks that have elapsed in the DigiWorld. However, in an earlier episode, Tai returns to the real world for hours and upon his return to the DigiWorld, only a few weeks have passed by.
Plot hole: (Ep. 5) The weapon Stephen finds in a desert is a H&K G36. He states that it's not a military weapon and is mainly a mercenary weapon. The G36 is used by several police and special forces units in the world, including the British SAS, which could suggest another nation's or British government branch's involvement. Comment was probably made to deepen the intrigue of the season plot.
Gold Fever - S2-E2
Plot hole: Roscoe and Enos are chasing the boys. They are well ahead of the Sheriff and go up into a semi with a conveniently made ramp to lose the cops. The dust was dissipated enough that Roscoe, coming up from the rear, could have seen the General in the trailer. Roscoe couldn't be that blind. Plus the trucker couldn't miss the movements of the truck settling down from the sudden adding of two tons.
Plot hole: In Episode 1-7: The Serene Squall, the Enterprise is at the edge of Federation space, and it is stated that it would take two days for a message to be received by Starfleet. Later in the episode, they have no problem establishing a real-time connection to Vulcan, which, according to canon, is only 16.5 light years away from Earth.
Plot hole: Dr. Adam Soong is initially presented as a discredited scientist, banned from the scientific community; he gets debarred and his funding revoked. And it's not an internal matter; he is publicly exposed for it. His daughter in episode 6 even finds out this information on Google. Several news articles call him "mad scientist" and such. However, this same person at the same time throughout the rest of the season has every bit of pull and influence, not just through undercover channels, but is treated with the utmost honor and deference by the NASA PR people at public events.
Worlds Collide: Part 3 - S3-E6
Plot hole: In their previous encounters with the Triceratons, the Turtles had to learn the hard way that the Triceratons breathe not oxygen but a combination of nitrogen and sulfur, which is detrimental to most Earth lifeforms, and thus had to wear special rebreathers. When the Turtles, Splinter, April and Casey enter Zanramon's throne room along with Traximus, none of them wear any breathing equipment to protect themselves from the hostile atmosphere.
Triumvirate of Terror! - S3-E8
Plot hole: At the Amazonian contest, the stadium is full packed with people spectating the event. When Joker attacks their queen and Wonder Woman, they do nothing. No panic, no revolt, no riot, not even a sound. Yet Joker just knocked out their queen, turned the other Amazonian warriors to his side with Joker Gas, and took out Wonder Woman, all in front of them. (00:11:30)
Plot hole: Lucien, Trustan and Aurora are somehow compelled to believe they are Mikaelsons, when no-one knew how to compel until Elijah compelled Aurora by mistake when they fled. So when did this supposed compelling happen? Did Elijah go back and do it later on? The siblings all had knowledge of him compelling them, so I'm confused exactly when they all learned of their ability.
The Aptitude Test / Oskar Gets a Job - S3-E9
Plot hole: Mr. Simmons asked that each student put their name on the test folders, but the folders already had names on them when he handed them out.
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)
Independent Dependents - S1-E7
Plot hole: When Helen goes into the air ducts, she simply removes the grates. They would not be loose like that, they would be firmly attached. When the team enters the basement they go through an ordinary door by picking an ordinary lock. A very high security installation like Axe Industries would not have such an insecure entry, even into the basement.
Explorers on the Moon: Part 2 - S3-E12
Plot hole: In the flashback, Wolf wakes up to find out Jorgen is in his bedroom. The problem is Wolf wakes up before Jorgen even enters the bedroom.