Pifias

When Michael is driving Haley to Sophie's house, the sun is shining strongly, but when Haley gets out of the car and starts walking to the house, the sky is completely overcast.

When Michael is driving Cat to Sophie's house, the sun is shining strongly, but when Cat gets out of the car and starts walking to the house, the sky is completely overcast.

When Cat is kicked out of the house, the sun is shining through the windows during scenes inside the house but the sky is gray and overcast as Cat runs through the trees outside the house.

When Georgie is eating a cupcake on the table, the cupcake changes back and forth during cuts. In one shot, the cupcake is half eaten and all over her hands but when the camera cuts to behind her, the cupcake is whole again, and Georgie is just running her finger around the cream.

When Georgie offers a cupcake to Francesca she puts it on the table and says "Cupcake?". When the angle changes to behind Georgie, she still has the cupcake in her hand.

While seen driving with his daughter, Michael at one point turns the steering wheel clockwise (to the right) while the car is veering left along a curve, thus revealing that the car is being pulled on a trailer.

About 50 minutes into the film, the time showing on the killer's camera is 4:56 pm and the sun is seen to be shining brightly. The location of the story is near Fairfield, Connecticut, where the sun sets at 4:24 pm on December 10th (which is the date showing on the camera screen). In a later scene it is pitch dark outside when the killer's phone screen reads 5:21 pm, but even if the sun had set shortly after 4:56 pm, it would not be totally dark only 15-20 minutes later.