Throughout the film, Catherine receives text messages from Chloe. The dates that appear on her cell phone do not progress. One date towards the start of the film reads "March 27th," and another towards the end of the film reads "March 25th," despite that meaning time is moving backwards.
In numerous shots involving taxis, the same Beck Taxi car and license plate number is used.
When Michael is talking to Anna via video-conferencing during their break-up, he minimizes the video-chat when he notices his mother (Catherine) peeking in to see what is going on, except when the camera angles change and he is shown running to close the door, the video-chat window is still shown on the computer screen.
When Dr. Stewart is in her son's room and checks a message from Chloe the date shown is Friday, 25 March 2009. The correct date should be Friday, 27 March 2009.
When Katherine is taking a shower and getting aroused, her nipples stick out a half inch. When Katherine and Chloe are in bed, and she's also aroused, her nipples are almost flat.
When Catherine is climbing the stairs at the end when Chloe and Michael are in her bed, she yells "Michael," but both times she's actually saying "David."
When Catherine catches Chloe with Michael, naked Chloe puts on a robe and is wearing a modesty patch on her vagina.