Continuity mistake: When Peter, Quagmire and Cleveland become cops because Joe trains them and they are all at Peter's, Joe has binoculars and is looking across the street and saying he is watching his wife Bonnie in her house. In just about every episode it is stated that Joe and Bonnie's house is right next to Peter's. So why is he looking across the street when their house is next to Peter's?
Audio problem: Just after Peter graduates from the Police Academy, he goes home to Lois and draws his gun in the kitchen, which gets Lois very excited. Every time Peter fires his revolver, you'll hear a soft, but distinctive clink briefly after each shot. This clink comes from shell casings hitting the floor, which revolvers make impossible. Revolvers are designed to eject expended shell casings only while its user is reloading, not after each shot is fired. Only semiautomatic firearms immediately eject expended cartridges immediately after having been fired. Unless I'm mistaken, the entire gunshot sound originally came from a 9mm semiautomatic pistol.