When Joe is in the hospital near the end, he wakes up and looks at the bedside table to his left. There is a clear shot of three white pills in a plastic medicine cup. When the camera zooms out, the nurse enters the room and the medicine cup is no longer on the table. The nurse then sets the cup down with the same pills in it.
The Jacksonport Polar Bear Plunge is held every year on New Year's Day, not Christmas Day.
When Joe and Sif get out of the pick-up truck at the drive-in theater, theirs is the only set of tire tracks in the snow but the truck is surrounded by footprints.
Where does JP go when he leaves the hospital? When Joe finally gets back to JP's family home late that day, the door Joe left open is still open, snow is inside, and the house is freezing.