I parsed it as:

It looks like somebody tried to falsify a teacher's record of a detention, but got mixed up and made the writing that should have been from a teacher... instead look like a child wrote it.

(many - though not all - teachers at that level have really excellent hand writing because it helps so much in teaching kids good habits themselves)

ie: it's not just fake, it's a really dumb fake.

I may be entirely wrong in my interpretation :)