 For the sake of continuity, Friday and Gannon always wore the same  outfits in every episode. According to Harry Morgan (qv), he and  Jack Webb (qv) decided to switch coats for one scene to see if  anyone noticed. Since only Morgan was in the scene, no one on the  set realized it until the scene had been shot. In the next scene,  Morgan has on the correct coat. This is the only incident of faulty  continuity in the series run.