When it shows Brad ripping the cable out of the electric meter at Sarah's house, it couldn't happen that way. Not possible.
Near the end when it shows Brad deleting Lucy's message from Sarah's phone, he is wearing leather gloves. The buttons won't work through gloves- try it.
When Lucy and her dad are eating breakfast in his house, on the morning they had planned to go to the college tour, he gets a call from his colleague. He then calls his wife as she's getting ready to leave for work. The time shown on her phone is 4:27 - late afternoon, when it should have been early morning.