When Bart gets all the students community service, the camera goes across the students all moaning about it. Lisa says, "Oh, no, no' yet her mouth doesn't move.
The Sea Captain says, "Not a looker among them," when the old folks are boarding the boat, but when Lisa asks him how he could miss Mr Burns' boat, he says, "Two glass eyes." If he has two glass eyes, he would not have been able to see if there was a "looker" in the bunch.