When Angelica leaves the hospital and communicates with Blake, the messages are sent as iMessage, later in the movie when Blake is re-reading Angelica's messages, they show as text messages.
When Cunnings sicced the dogs on Angelica, her coat sleeve was covered in mud. However, when she's being chained in the Cunnings's basement just moments later, there is no visible mud or staining on the pink coat.
When Blake stops by the Sheriff's office and talks to the two deputies outside, a Sheriff's SUV is seen in the background, dark in color. Moments later when the two deputies decide to pay a visit to the Cunnings's farm at Blake's prompting, they arrive in a white SUV.
When the two deputies arrived at the cabin Blake was staying in, there were many lights and lamps turned on throughout the entire home. The deputies told Blake he needed to file a missing person's report in person down at the Sheriff's office, he left the cabin in haste, leaving all the lights turned on. However, when he returned back to the cabin later that evening, almost all lights were extinguished.
After five months caged in a cellar, Angie still has makeup on.
When Angelica follows the Cunnings back to their property, she climbed over the locked fence to follow the driveway leading to their home. This was a moot point. She could more easily have walked around the tree to the left of the gate to bypass it.