Audio problem: When Stewie knocks his glass off the table, it makes a shattering sound, but it doesn't shatter.
Audio problem: When Peter is telling the guys about the doctor visit, he starts crying and knocks his beer glass off the table. It makes the sound of glass shattering, but the glass on the floor isn't broken at all.
Barely Legal - S5-E8
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.
