Revealing mistake: When Jonathan has the red balloon float to the sad young girl, we can see the balloon's guide wire just as she takes hold of it, while she and her brother are on the bench. (00:06:30)
Highway to Heaven (1984)
1 revealing mistake in season 2 - chronological order
Starring: Michael Landon, Victor French
Another Song for Christmas - S1-E13
Revealing mistake: The smoke from the supposedly broken vehicle is obviously not coming from the tailpipe. It is coming from the trunk.
Mark Gordon: Cute, Jonathan. Real cute.
I Was a Middle Aged Werewolf - S4-E5
Trivia: When Mark is in the motel room watching TV, the movie he is watching is "I Was A Teenage Werewolf", starring a young Michael Landon, star of this show.