Revealing mistake: Throughout the entire series there is one staircase upstairs and two downstairs. And, they more than likely are not the same staircase because the two downstairs are on opposite ends of the house.
7th Heaven (1996)
Episode list - season 4
Starring: Jessica Biel, Catherine Hicks, Stephen Collins, Beverley Mitchell, Happy
More mistakes in 7th Heaven
Rev. Morgan Hamilton: We cannot fight hate with hate. What are we teaching our children today? That will make things better tomorrow?
Trivia: This episode has the infamous scenes in which Mary wants Matt's help with kissing. Supposedly, the original script involved the siblings actually kissing for practice, but Jessica Biel (playing Mary) and Barry Watson (Matt) refused to do it.