The Thing About Heroes - S4-E10
Factual error: "The Thing About Heroes" When Mac has a flashback to an incident when he was 14 years old (in the 1970s) and gives the money to Bobby Toole the twenty-dollar bills all have the large 20 on the back side. This was not issued until 2004.
Chosen answer: Probably to broaden the scope of the show's plot and give the audience a chance to see the characters in a different setting, People act differently at home from the way they do at their workplace. By the ninth season, the characters would have become overly familiar and predictable. It gives the writers a chance to do something different with them.
raywest ★