Normal Boy/Birth of a Salesman - S1-E3
Other mistake: When all the school kids are meeting outside the school when the meteor approaches, some of the background characters appear twice in the same shot.
Safety First/Crime Sheen Investigation - S1-E12
Other mistake: During Crime Scene Investigation, Jimmy explains his costume to Carl and, while saying "Sherlock Holmes", his chin goes into his jacket. (00:14:38)