One of the two (the male) who descend into the mine to save their friend, holds a flashlight and a handgun. As he turns to the camera, the flashlight is clearly seen to be off.
When they discover the presence of Anthracite at the mine, a character announces they've found C15H11O (which is the elemental composition). However, he pronounces it as C15, H11, "dash zero", when it should be "oh" as in the letter, which stands for oxygen.
The team standing directly over the metal grates covering the coal fire is unreasonable. The escaping gas would be toxic and the heat unbearable.
The keep's 'Kentucky' license plate reads neither the state, atop, nor the county name, on a blue swath, below.
From 0:34:46 - the "electric barrier" power supply, connected as it is, is shorted out.
At 0:06:45 -the red fireplug along side the road would not be there unless there was a town or other important structures very close by.
Where they drive through the hill in the beginning of the movie that place is more than 2 hours away from the " Carter caves" statement mentioned before and that place is called " Red River gorge" and the technical name for the exact place is called " Nada Tunnel"
From 0:36:05 -Shawn isn't actually lowering anything.
While in the SUV one character complains about: "none of the roads are on the maps" and: "they exited the highway four hours ago" yet, clearly, the road on which they are travelling is well maintained as is the bridge they cross; and there is a brown sign with white lettering for the nearby Otter Creek Recreational Area. Which would put them approximately 50 miles from Lexington, Kentucky.
At 0:43:35 -the group abandons their Jeep four wheel drive simply because one wheel is stuck in a shallow rut.
From 0:03:34 -a town which has been written about for decades because of a raging fire in a coal mine is not located on any map.
At 0:41:36 -Arianne manages to climb out of the pit, unassisted.