Sedna is the closest thing I can see to his theory. It's red, highly elliptical orbit (although no where near close to Earth). I really can't buy the whole aliens lived there and came to Earth to mine gold to save their atmosphere though.
Other than the fact that Pluto's orbit is elliptical is there any evidence of another large mass object orbiting the sun? Is it possible that (enter amount of years here) that some object passed by our solar system and "pulled" Pluto out of it's orbit before it left?