It Happened 'That Night' - S3-E1
Character mistake: Emily's mom tells Emily that reporters were there to talk to them about "Emily's missing remains." It's supposed to be "Allison's missing remains." (00:17:00)
Blood Is the New Black - S3-E2
Continuity mistake: When Ezra is talking to Aria's mom in the classroom, she is writing on the chalkboard. After a brief moment, she is erasing information on the board, and we see it gone, but Moments Later the writing is back on there.
Continuity mistake: When Spencer and Toby are having lunch, she lifts her water bottle. Between shots, the hand she is using changes. (00:46:35)