Revealing mistake: Judging by the interface, the video of Jenna and Toby sleeping together is played through Windows Media Player. When this program is playing a video, the big blue "Play" icon becomes a "Pause" icon. But whenever the video of Jenna and Toby is playing, the "Play" icon is still showing. It's obviously not an actual video being played.
Pretty Little Liars (2010)
1 revealing mistake in show generally - chronological order
Starring: Lucy Hale, Ashley Benson, Sasha Pieterse, Shay Mitchell
Someone to Watch Over Me - S1-E20
Continuity mistake: After Jenna is slapped by Hanna in the bathroom a single tear streams down her right cheek. The next shot of Jenna shows the tear track on her left cheek.
Trivia: Lesley Fera, who plays the mother of Torrey DeVitto and Troian Bellisario in this series, is, in reality, only 12 years older than DeVitto and 13 years older than Bellisario.