Phhsshshshhht, OBVIOUSlLY the butle- err, servant did it.
"Didn't figure it out?" made me think there was another ending. (not sure exactly what he said)
Or DID he? My favorite thing about the censored characters is that you can never really know! (Some of my interpretations have him innocent.)
And yeah, the final line was pretty vague, but I just wanted to tie up the story somehow and thought that was the best way.
It's always the butl- er servant, if it isn't, it's me, out of anger, that it isn't the butler.