Character mistake: When the Brady kids are practicing for the talent show, instead of saying, "Come on, Pete," Marcia says, "Come on Chris," which is the actor playing Peter's real name (Christopher Knight). (00:14:30)
Mine Your Own Business - S1-E4
Character mistake: When Shaggy and Scooby order Sarsaparilla at the saloon, Scooby says "Two" but he appears to be holding up three fingers.