Dawson's Creek (1998)

Valentine's Day Massacre - S3-E14

Factual error: This episode is set on Valentine's Day, but there is a shot of the front of the school where a girl is wearing shorts. It snows in Massachusetts in February, where Capeside is set.

Valentine's Day Massacre - S3-E14

Revealing mistake: When Jen goes to visit Henry at the hospital, he is eating a small individual-sized Jello. There is another identical Jello on the same tray, in front of Jen when she sits down to talk to Henry. You can see that the corner of the Jello lid has already been pulled up rather noticeably. This is probably to make it easier for Michelle Williams, the actress to be able to open the Jello quickly during her scene.