Catch A Falling Star - May 21, 1979 - S2-E10
Character mistake: In the preview for this episode, Charlie has trouble getting his countdown straight. He shouts that Sam is on in 50 seconds, then 47, then 48. In the episode itself, the mistake is corrected with a rather obvious overdub, changing the final number to 43. (00:02:05)
Character mistake: The title card says "Plummers Academy" instead of "Plumbers Academy."