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: Guards at a security checkpoint attack Varrick and Bolin, because a wanted poster identifies them as fugitive traitors. The problem is that poster cannot have been there. Varrick and Bolin escape in the previous episode (Battle of Zaofu) but are captured minutes afterwards. (So, no posters needed.) The next day, they escape again by blowing up their imprisoning train car. Their captor, Bataar, thinks they are dead. Indeed, Varrick intended to die. Later, Bataar is actually shown reporting them dead. One might argue that the poster wasn't a wanted poster, but one that warned people about the empire making an example of the traitors.This argument is too flawed: The empire had many examples already, some very high-profile. And a propaganda poster must be placed in plain sight, not in a security booth corner especially designated to let security guards compare the passing individuals. (00:14:00)
Plot hole: When Connie uses the wish machine to make Malloy small again, she instead wished for Ethel's breasts to get significantly bigger. However, in the next scene Ethel's breasts are back to her regular size. The plot shows that the wish doesn't wear off, and someone else would have needed to wish for Ethel's breast to get smaller but no one did.