^Yah, I saw that shortly after I hit "submit" on my post.
Less sane fans are suggesting that they deliberately messed up the credit in order to avoid the Meriwether stigma, and force people to evaluate the episode on its own merits. (And I guess, what, Meghan's tweet is some kind of gotcha?) Okay.
I think I want a plushie of Rarity in her Hazmat suit.
EDIT: *slaps forehead* This entire episode was a riff on (ripoff of?) "Wallice and Gromit's The Curse of the Were-Rabbit." I don't know how I didn't see it, but it's really obvious once all the similarities are pointed out: http://archive.heinessen.com/mlp/thread/15334932
I feel a little let down, now.