Forum:Heinz can grow facial hair?

Isn't this an example of continuity error for the Unfair Science Fair and Crack the Whip episodes?

In crack the whip the reason behind his invention was because he was angry with people who can grow facial hair. BUT in Unfair Science Fair we see in a flashback when Heinz takes up poetry we blantantly see him with a small beard a cliche of being a poet.

So what is the explaination?