Muppets never lie? *laughs* Scooter must not be a Muppet them. The Sly Stallone episode cost him his license to mup.
As for Muppets never acknowledging they're puppets, that may be true in routine work, although they've poked at the fourth wall (Kermit calling attention to his drinking through a straw) and, in fact, one episode of "The Jim Henson Hour" took a wrecking ball to that wall when the camera pulled back and the characters started freaking out because we could see their puppeteers. However, this is one commandment that Disney seems dead-set on keeping, even to the point of erasing arm rods. I don't mind the rods, but it seems like a slight to the puppeteer to not acknowledge their craft. It's kind of like refusing to admit that their non-CGI cartoons are a series of drawings done by artists.