Maybe I'm missing something everyone else has seen, and I'll look like an idiot (again), but how did the Loon do that bit with the pillows-out-of-nowhere while teaching the third-year Hufflepuffs? It doesn't seem like it could've been one of his song-magics -- lasting most or all of the class? -- and besides, the kids don't mention him wearing his helmet, or music playing. The only halfway-reasonable explanation I can think of is that he requested someone else, such as Twonky in particular, to act as a "teacher's assistant" -- house-elves, based on what we've been shown of their powers, could certainly do a bang-up job -- but wouldn't Doug have mentioned that in his narrative?
-----
Big Brother is watching you. And damn, you are so bloody BORING.
-----
Big Brother is watching you. And damn, you are so bloody BORING.