Revealing mistake: When Kenan has the spider on his back it is blatantly a fake one. When Kenan panics, the spider doesn't move.
Revealing mistake: The parrot is a very obvious stuffed toy.
Visible crew/equipment: When Roger is leaving you can see outside the door that the background is a painting.
Revealing mistake: When Kyra goes upstairs after kissing Kel in the opening scene, it's clear the stairs don't go any further as you can see her shadow on the wall climbing down backstage.
Continuity mistake: The amount of foot dust changes from when Chris come back to when Kenan grabs some.
Continuity mistake: Bloodbath's lead disappears between Kel bringing him out and him chasing Chris a few seconds later.
Factual error: The police artist has 1 pencil but manages to get loads of different colours in the drawing.
Continuity mistake: When Kel throws the foot dust the first time, a girl at the back is coughing despite no dust meeting her.
The Lottery - S2-E3
Continuity mistake: At the very beginning, when Kenan is shown in Rigby's, the clock changes from 8:00 to 9:25. (00:03:00 - 00:03:30)
The Lottery - S2-E3
Continuity mistake: When Kenan is putting the cans on the counter at the beginning, the cans swap places. Watch the green one. (00:03:30)
The Lottery - S2-E3
Continuity mistake: Kenan gets the tickets for him and Chris from on top of the machine not from the machine. (00:08:50)
The Lottery - S2-E3
Continuity mistake: When Kenan is getting a ticket for Kel, he goes to put it in the machine but misses. The next frame it has disappeared. (00:09:35)
The Lottery - S2-E3
Revealing mistake: The pink container in Kel's bags is very obviously empty by the way he handles it. (00:13:25)
The Lottery - S2-E3
Revealing mistake: The goldfish Kel grabs is very obviously a fake. (00:18:50)
The Lottery - S2-E3
Audio problem: When Kenan is being hit by the swordfish, the sound is out of time with the actions. (00:20:25)
The Lottery - S2-E3
Revealing mistake: When Kenan hits Chris in the mouth with the apple, you can tell it was placed in his mouth because he managed to bite the apple, and take a chunk of it out. Normally an apple like that would smash your teeth.
The Lottery - S2-E3
Continuity mistake: The Lottery numbers change from the draw to when claiming.
Who Loves Orange Soda? - S2-E4
Factual error: The doctor, on his fist look at the x-ray, claims Kel's ribs are bruised. Without looking more carefully, he wouldn't be able to say that. (00:05:10)
Who Loves Orange Soda? - S2-E4
Continuity mistake: When Kenan and Kel are making the bet, the clock on the wall changes time. (00:08:00)
Revealing mistake: Kel is in the Orange Rain and if you look at the road you can see it is just paper by the way it warps. (00:09:50)
Answer: He's simply enjoying doing it himself. Especially since he likely believes he can do it better than she can.