Factual error: The police artist has 1 pencil but manages to get loads of different colours in the drawing.
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)
Answer: He's simply enjoying doing it himself. Especially since he likely believes he can do it better than she can.