Revealing mistake: About a minute into the movie we see Ethan Hawke waking up. He has a tattoo on his left pectoral. He then goes to the sink and mirror and the camera is directly behind him. He drops out of shot and in the same shot reappears in "the reflection" as he splashes his face with water. His tattoo is still on his left pectoral - all he's done is drop out of shot, move forward a few paces, turns around towards the camera and reappear as the mirror reflection. They've forgotten to either flip the image around or put the tattoo on the other side. (00:06:00)
Revealing mistake: In the scene where the group finds out that Jasper has betrayed them and then Bishop uses the flash-bang, the group splits up, and Iris and Capra get into an SUV. Very shortly later, when it goes out of control and crashes, you can see a stunt driver in the SUV wearing blue elbow pads and holding onto the roof, before the SUV hits the ground. (Slo-mo may be necessary.) (01:31:55)
Revealing mistake: Anna hot-wires the truck so she and Alex can go get help. As they are driving away, tire tracks from the camera vehicle in front of the truck are visible in the snow.
Revealing mistake: There are several problems with lighting and time sequence during the nighttime forest scene at the end of the movie. The tall trees are backlit by a very bright light, obviously studio lamps for they are much too bright to be natural moonlight. And when they emerge from the dark forest five minutes later, it is daylight and the sun is already several hours over the horizon.
Revealing mistake: The snowfall during the forest scene is very fake-looking. Snowflakes change size and brightness randomly, and twirl around in the air in a very unnatural pattern.
Revealing mistake: Despite complaining of the bitter cold inside the police station, no condensation can be seen coming from the characters' breath.