Easter Egg - Charlie Hibbert (actor Andrew Sensenig) can be seen multiple times hiding in the background watching Jack & Claire. This is most noticeable in the Pool Scene where he is clearly visible in the background with a video camera. This is the exact footage used later in the hand held camera scene that Jack watches.
The sign above Jack's head in the library used to say "Non-Fiction" but Aaron Koontz, the director, asked for it to be changed in post-production to read "Fiction" to better speak to Jack's psyche and mental state.
The role of Det. Dawson was originally going to be played by Barbara Crampton, reuniting her with her 'We Are Still Here' co-star Andrew Sensenig. But before shooting Barbara had to pull out due to a scheduling conflict.