Plot hole: Whenever Leela arrives and everyone starts beating up Fry to make him cry out the emperor, it shows Dr. Zoidberg pinching his leg and later, sitting next to the wall, tired out with Bender and Amy. However, if he's there, then what is keeping the Trisolians from coming through the hole in the door that Zoidberg was plugging with his claw? (00:19:40)
Plot hole: In the sewer, the guy with the big forehead starts singing with his guitar and a crowd gathers around. But you can see Leela's parents standing in the crowd and having no reaction to their daughter whatsoever, despite them knowing what she looks like. Considering later episodes, this is a bit confusing.