One of the definitions of error is, "an accidental wrong action or a false statement not made deliberately."

You deliberately Googled for reviews of The Residents television show, but found a review of an essay written by Matt Groening (yes, the guy who does The Simpsons) from 1979. So granted yes - that was an error on your part.

You then deliberately copy pasted/lightly rewrote it and deliberately entered the stolen content into a contest. Even if you'd included the source, none of it was written by you, so you were deliberately trying to defraud the community.

I believe the only thing you are sorry for is getting caught.