Continuity mistake: Cold War: Kenan holds the melon with the holes facing down. Yet no juice comes out, but it does when Chris looks at it. (00:04:05)
Revealing mistake: Star Is Peeved: When Kel is eating the sugar cubes it is clear he isn't eating them at all. (00:07:50)
Continuity mistake: Get the Kel Outa Here: At the start of a 5 minute scene, the clock in Rigby's says 4:30 approx. At the end of the scene, the clock says 4:40. (00:13:00)
Continuity mistake: In the episode when it's Kenan's birthday, Kenan and Kel are looking for Kenan's present in Kenan's parents room. As they're searching, Kel throws some of Kenan's parent's clothes all over the place. But then when Kel throws the snowglobe, there is practically no mess, but just a few clothes on the floor - less than before. Some clothes on the bed disappear as well.
Continuity mistake: In the episode where Kel is banned from ever going in the Rockmore house again, Kel sneaks through Kenan's window, scaring Kenan. Kenan jumps back in fright and knocks the lamp from his bedside table and it rolls onto his bed. However in the very next shot the lamp is suddenly back and upright on the bedside table. In the next shot the lamp is now back on the bed.
Continuity mistake: In the episode when there is a rat in the store, there is a scene where Kenan and Kel are discussing the rat. There is a lady in the background holding a green shopping basket. Then in a following shot the same lady is now suddenly holding a red basket. Cut to the shot where she runs out of the store screaming, and suddenly her basket is green again.
Visible crew/equipment: When Kenan and Kel are at the White House, after Kenan saved the President's life, and was therefore allowed to visit him - Kenan and Kel open the President's secret hideout, by pulling a book on the bookshelf. Inside the hideout, there is a clear tape-mark strip on the floor. In following shots when the President walks inside, the tapemark strip has now vanished.
Continuity mistake: When Keenan is yelling at the kids playing with the water guns, there is a clip board on the counter that disappears.
Continuity mistake: In the episode when the president comes into Rigby's, near the start Kenan supposedly fixed the slush-o machine, yet it isn't fixed properly and slush-o sprays out and completely covers Chris. As the scene continues, the wet patches on Chris's apron completely change. At one point there are only a few patches dotted on the apron, then suddenly the apron is completely soaked again.
Revealing mistake: Cold War: Kel misses hitting Roger when trying to wake him up.
Continuity mistake: Cold War: At the very start it is clear that Kel does not spit out the mouthwash into his hat. This is confirmed by when Kenan throws it no liquid can be seen.
Revealing mistake: Mo Sweater Blues: When Kenan and Kel are using the high pressure hose to clean the sweater, if you look closely you can see that the sweater is pulled off the wall.
Factual error: Diamond are for Roger: The ease with which Kenan open the safe door is unrealistic. I have worked in a bank, and those doors are not light. It wouldn't move that quickly, that easily.
Continuity mistake: Mo Sweater Blues: When they arrive at the restaurant the stain on the sweater has changed shape.
Visible crew/equipment: When Kel gets up to get more water you can see one of the cameras.
Doing Things The Hemingway - S1-E3
Continuity mistake: Kel is attempting a life goal and attempts to put 50 grapes in his mouth. When he spits them out there is about 10, nowhere near what Kel then claims is 33 grapes.
Doing Things The Hemingway - S1-E3
Revealing mistake: Kel takes the VCR player without unplugging it but Roger was watching a video seconds before.
Doing Things The Hemingway - S1-E3
Revealing mistake: The clouds are very obviously a set-drop when on the top of the CS tower.
Doing Things The Hemingway - S1-E3
Continuity mistake: When Kel jumps into the window cleaners' bench it's only a fraction down from the roof. no more than 6ft. Next shot with Kenan the bench is further down.
Continuity mistake: When Kenan and Kel are in Kenan's room there are 2 socks hanging out of the dresser the one on the left keeps changing positions.
Answer: He's simply enjoying doing it himself. Especially since he likely believes he can do it better than she can.