Get The Kel Outta Here - S2-E8
Revealing mistake: When Mrs. Rockmore opens the door there is a painted house visible outside. (00:02:55)
Get The Kel Outta Here - S2-E8
Revealing mistake: When Kel throws the masseuse, it is obvious he lands on a crash mat due to his height when supposedly on the floor. (00:06:30)
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.
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)
Get The Kel Outta Here - S2-E8
Revealing mistake: Kel walks away the wrong way when told he is not allowed in the house ever again. (00:07:50)
The Lottery - S2-E3
Revealing mistake: The goldfish Kel grabs is very obviously a fake. (00:18:50)
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)
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.
Answer: He's simply enjoying doing it himself. Especially since he likely believes he can do it better than she can.