i used this in a group game the other day and it was hilarious.. it was stolen from me.. and i asked him to attack me so i could shuffle my library.. awesome!!
Did you want your library shuffled? Did he know that but still granted your request?
That's like me in a game where my opponent put out a Howling Mine and I said "Awesome!". My opponent said something like "you know that it was a bad move when your opponent likes the card you put out"