Revealing mistake: The headlights on Hayley's car are fake (i.e, blocks of white to represent headbeams). (00:30:36)
Continuity mistake: Different views of Sarah riding in the passenger's side backseat of Hayley's car show her either leaning into the corner with her left arm stretched across the seat's back or her back against the seat with her right arm extended along the window. (00:28:50 - 00:29:32)
Continuity mistake: After Sara's mother sits at the table, the left side of Sara's hair suddenly has two clumps of strands running down her cheek and flipped in front of her chin. Sara's hair changes a few times with different camera angles. (00:44:52)