Visible crew/equipment: In the scene where Noah picks up Aidan from the floor, you can see a crewmember in the shadows up the stairs when they are going into the next room. (Time)

Continuity: In the scene where Rachel bursts into Noah's apartment after he was killed, play it slow-motion when she flips the chair around. You can see up to half of his normal face & hair, with no decomposition visible, or hair loss.

Revealing: In the scene (in the extra/cut scenes) where Rachel an her sister are talking in the dead girls room, her sister opens the closet and we saw a flashback of the dead body sitting in the floor. If you use the pause key, you can see a drawing in the floor indicating where the girl should stay to make the shot. Second later we see the closet without the chalk drawing.