When Ethan first finds the locket at Greenbriar, it is engraved with two sets of initials in a simple script font. When Ethan first gives the locket to Lena, the initials are the same, but the script is much more intricate and elegant.
The writing on Genevieve's locket changes from a simple type to a fancier type.
The matter of the script changing might not be a goof. Lena's power might change the script unconsciously in her presence.
At about the halfway point, when Ridley has brought Ethan to the Ravenwood home, Ethan is straining so much to speak, that his upper lip and part of his cheek is soaked in perspiration. But when Macon asks Ridley what she has done to him, and the camera angle changes to over Ridley's shoulder, his face is completely dry.
(at around 1h 28 mins) During the conversation with Macon, Ethan is shown from two different camera angles. One of the shots is a mirror image judging by the inverted world map on the wall behind Ethan.
Ethan is reading the book "You Get So Alone at Times That It Just Makes Sense" by Charles Bukowski, but the poem is not in that book. The poem was published "Burning in Water, Drowning in Flames."
Gatlin is a fictional town, but the Battle of Honey Hill was a real Civil War battle in South Carolina. The film gives the wrong date for it: December 21, 1864. It actually took place November 30, 1864.
The town has less than 400 residents but has a football stadium that could easily hold over a thousand with a very expensive artificial turf field.
An overhead full moon cannot occur in daylight, especially around Christmas, and in South Carolina. A full moon rises at the same time the sun sets, and nightfall follows soon.
When Lena and Ethan go to the movies you can overhear Ethan introducing her to Link before Ethan pays, but Link isn't there until later. However, a deleted scene shows that introduction.