When Hermes is poised to press the eject button the crew jump out of the box and he pulls his hand away in shock. When we pull back to outside the ejection port we see Hermes finger still poised over the eject button again.
In Season 3's I Dated a Robot (2001), Fry asks if there are an infinite number of universes after seeing the cowboy universe, and the Professor replies, "No, just the two", yet this episode features multiple universes.