Continuity mistake: On the video of Ian supposedly killing Alison, we see her arm fall to the ground with her "Alison" bracelet visible. But in a later scene where Emily watches Ian put his bag in the athletics room, we cut back to the video and Alison's arm suddenly has a sleeve covering up her bracelet. When we see the video again later in the series, her bracelet is visible again.
Continuity mistake: In the scene when Ezra rides up behind Aria in the Limo, you can see his hand up to his head, as if on the phone. The camera then cuts to Ezra in the Limo and you see him answer his phone. (00:22:25)
Factual error: Emily is supposed to meet Paige at a karaoke bar at the intersection of 202 and W. Chester Pike, however this intersection is actually an overpass. 202 crosses over top of West Chester Pike, but never actually intersects it.