Continuity mistake: When George Maharis walked out over a salary dispute, his character Buz was said to be in the hospital and was absent for about 10 episodes. (The tiff finally resulted in his removal from the series in the 4th season.) Airing out of production order, however, rendered the bizarre third season phenomenon of a supposedly hospitalized Buz who re-appeared periodically as though he'd never been away, then was "sick" again in the next episode.
Hey, Moth, Come Eat the Flame - S3-E11
Continuity mistake: In this episode, without explanation, Todd is suddenly driving a brand new 1963 Corvette instead of the previous 1961 model. But because the episodes were not aired in production order, the old car reappears six episodes later in "A Gift for a Warrior."
Where Is Chick Lorimer, Where Has She Gone? - S3-E13
Revealing mistake: Tod parks his car across the street, facing left. While standing in front of the house Ellen and Peter run to Peter's vehicle and drive off to the right. Tod goes back across the street and gets back in the Corvette. The image is then flipped to give the illusion that he is driving in the direction Ellen and Peter went. (00:21:00)