When Mary shoots the creature through the door, no holes appear in the door or the glass.
The hogs that were stolen were not 100 lbs each. They were maybe only 20-30 lbs when Caleb fed them.
The movie is supposed to take place around 1966-1968 but John's Chevy truck has an inspection sticker (actually two) that expire in May of 2012.
We're told that the events happened in "1966 or 1967", but the wife calls the sheriff by dialing 911. The first 911 call was made on February 16, 1968.
Dale's hat in the movie is a curved brim style ball cap - a style started in the very late 90's. A cap in the movies time frame would be more a straight brim mesh back 'truckers' style ball cap. His jeans are also a style from today (baggy bottoms with the length bunched at his boots) rather than either the 'flood' style from that time period or the 'rolled-up' style also from that time period.
Story is supposed to take place in "66 or 67" but John's truck is a 1969 Chevrolet.
Story is supposed to take place in "66 or 67" but front end of Ford van on logging site appears to be from The 2008 & later body style.