Continuity mistake: When everyone is inside the Museum, Carl offers a Cherry Flavored Fruit Chewy to Cindy. She jumps at it and takes a bite, then clears a stain on her lips with a handkerchief, which she then drops. Carl bends down and picks it up, and then Cindy jumps with a boost from Carl. But in the next shot of Carl, he doesn't have Cindy's handkerchief.
Continuity mistake: In the Great Egg Heist, When they arrive at the Museum, Jimmy gives everyone shishkabob-shaped earplugs for Libby's scream. But in the next shot, if you look at everyone's ears, there are no earplugs. Also, in the next shot, next to Libby you can see Carl putting his hands over his ears. This is impossible because the pointy ends of the earplugs would stab Carl's hands.
Continuity mistake: In the episode "Men at Work", In the end, Jimmy is trying to destroy that flying burger place. In one shot his computer shows that it has already destroyed pizza clown, but the next shot switches to the burger place, destroying pizza clown after it has already come on the computer as it being destroyed.
Audio problem: In the episode where the Wheezers obtain super powers, at the end of the episode, they are all singing their "Sitting and Singing" song surrounding the flaming duck. When the camera cuts to Carl putting his glasses on, the song can still be heard, but everyone's mouth just keeps saying "Standing, and standing, and standing," even though there are more words heard than just that.
Factual error: Jimmy tells Carl and Sheen they were sent back 200 million years and throughout the episode, they say they are in the Cretaceous period. The Cretaceous period actually started around 145 million years ago. They would actually be in the mid Jurassic period. Also, the tyrannosaurs didn't appear until much later in the Cretaceous, around 70 million years ago.
Factual error: As the villains are approaching to Earth, South America is shown just under Asia, connected to the Arabian Peninsula and the southern tip of India. The two continents are nowhere near enough to each other to be seen at the same time from space, much less connected. They are on opposite sides of the Pacific ocean, over 10,000 miles (16,000 km) apart. (00:06:45)
Plot hole: In "The Evil Beneath", after Jimmy, Carl, and Sheen escape Dr. Moist's secret lair, they fly back in the hover car where they start seeing some evil fog shadows, and take off. Earlier, being out of fuel was the cause of the hover car's crash landing, but somehow it's been refilled to escape.