In the video, which, it should be noted, was posted to Zac Efron's YouTube page, Pattinson explains who he was nominated by (Efron, natch) and delivers a qualifying statement that makes him immune to any criticism of his execution of the challenge. He is also utterly charming in the process. Oh, and it turns into a bit of a wet T-shirt situation. So there's that.
Good for you, Robert Pattinson.