Continuity mistake: After Garcia traces the phone call, Morgan and Rossi are shown driving to the area of the cell tower. When the shot is from outside the car, the car is a 10th generation (07-14) Chevy Suburban. When the shot changes to inside the car, it's an 11th gen (15-16).
Character mistake: When the unsub puts the lock on the woman's collar, he hooks it onto the part where a leash would go. She could easily take the collar off. Later, the lock is on a different hook that is pushed through the collar, so she would not be able to escape. (00:19:10 - 00:33:30)