Revealing mistake: When Sheriff Miguel Acosta answers his phone right before he finds the mask in Gustavo's room, he doesn't actually answer the call, and his phone is still in call mode when he raises it to his ear.
Other mistake: In the third scene, where Emma is texting Kieran, the time stamp on the text reads 3:32 PM. She then goes downstairs where her dad is waiting and says she's "late for school." If that timestamp was accurate she'd have missed almost all of school.