Factual error: The corpse's head in the cafe changes position between shots. (00:34:00 - 00:35:00)
Plot hole: Towards the end the Rich Purgers call for reinforcements, and Shane, Leo, Eva and Cali are hiding behind a wall. A guy somehow opens a door in front of them (without being seen by the three facing him), exposes himself and shoots only Shane, numerous times, to cause his death. He should have been spotted by the people looking in his direction. Also, if he was that well hidden he could have simply sprayed the entire group. He unloaded 5 or 6 shots to Shane's chest...when he could have taken them all out.
Continuity mistake: The girl that Jesse brought into the house, Penelope, was wearing a blue skirt with leggings when they arrived at the house. However when she walks around the corner to take off her shirt she comes back with just black leggings on.
Continuity mistake: Ben shoots the last bottle used as a target on top of the red drum. After that, he reloads his gun while chatting with his two partners, and magically, multiple jars and bottles appear on top of the drum so he can continue practising. (01:18:25)
Factual error: Writer/director Adam MacDonald boasted that he studied black bear predatory behavior and black bear attacks on humans for years in preparation for making this film, because he wanted to depict a black bear attack in as factual and as authentic a manner as possible. But, at the most crucial point in this film (when the black bear actually does attack Alex and Jenn), factual accuracy goes out the window. As Alex and Jenn cower in terror, the bear lunges into their tent and bites into Alex's leg; whereupon, Jenn fires a can of bear spray (a stifling pepper-based chemical) point-blank into the animal's face. The startled bear retreats for a moment, but then lunges into the tent again, dragging Alex outside and killing him; thereafter, the bear continues pursuing Jenn for the remainder of the film. However, according to years of extensive study by the University of Calgary, no bear has ever attacked a human after the animal was sprayed with bear spray, much less resumed an attack, as depicted in this film. To date, the success rate of defensive bear spray is 100%. So, the factual accuracy of "Backcountry" was abandoned for the sake of cheap thrills.
Other mistake: When Jordan drops Rusty's truck into the compactor, the excavator and its claw seem just too small for the job. You can see the truck has been sawed shorter as the truck's rear axles stay on the ground while the cab goes in the compactor. There is no possible way for the truck to snap in half like that when lifted. This small excavator would just simply have flipped over trying to raise the truck by the engine compartment.
Continuity mistake: Nicole is in Tina's house, asking Matthew about the baby teeth. Trouble is, this scene is after Nicole has been kidnapped and locked in the van. (01:27:20)
Continuity mistake: When the car with Alice goes over the cliff, and when she then exits, she is wearing shoes. When she awakens and begins climbing (and afterward), she has none.
Visible crew/equipment: When Major Carver gets in his car to chase after "David", the entire camera crew is reflected in the side of the car when it's reversing.
Factual error: The picture of the bomb switch shows an Arduino Pro Mini. The Arduino Pro Mini was released in 2008, not in 1975. (01:21:20)
Suggested correction: SPOILERS: The ending of the film reveals that the Fizzle Bomber is an older version of the Agent, who still has a functioning time machine. This simply shows that he is using parts from the future for his bombs.
Factual error: Scarlett and George use the Rose Key to translate the inscription on the back of Flamel's ancient tombstone, and it translates into a rhyming English lyric puzzle. Problem is, they are translating this lyric puzzle from Aramaic (an ancient and virtually dead Middle Eastern language) to modern English. Aramaic would not and could not translate into rhyming modern English.
Continuity mistake: During the car chase, the white jeep goes from damaged to undamaged between shots. (01:08:00 - 01:09:00)
Continuity mistake: At the end when Sarchie is hugging his wife, in one shot the bandage on his arm has unravelled. In the next, it is neatly wrapped.
Continuity mistake: When Kat first visits the detective, she sits on the couch and drinks beer. Behind her is a table with a lamp and a green bottle of beer. In the next scene the bottle disappears, and reappears in the next scene. (00:34:00 - 00:35:00)
Revealing mistake: JR is in the weapon container of the crazy dealer, who passes him some of his goods. JR ends up holding in his right arm a MP5K and an M4A1, which combined are about 5 kilos, but then he passes him an M60 Machine Gun, which weighs over 10 kilos and that the relatively diminutive protagonist just handles throughout the scene gripping it with his left hand and making no effort whatsoever. (00:25:20)
Continuity mistake: The cut (s) on Jim's lower left lip frequently changed. At the "Wildcats" game, there appeared to be three slits, but they were not easily seen and it wasn't apparent how he got them. In the earlier beating he got from Lee's Heavy #1 and 2, his lip didn't get cut and the previous cut on his lip was not visible. When Jim met with Neville, he had three distinct vertical slits/cuts on his lower left lip. Thereafter, the appearance (presence or absence) of these cuts continued to vary. (01:25:55 - 01:31:45)
Revealing mistake: At the end the sides of the grave (which Jack just had dug by spade) are too perfect. Only an excavator could get such neat sides.
Character mistake: Mitch states that he is Pisces then goes on to state that his birthday is 25th of March. The Pisces period goes from 19th February to 20th of March. Mitch would actually be Aries. (00:35:00 - 00:37:00)
Continuity mistake: Carrie's height changes constantly.
Other mistake: It is stated by the caption ("The far East; 3 years later") that the events of most of the movie take place 3 years after the prologue. Thus, both Nicolas Cage and Hayden Christensen have made it to China and learned flawless Chinese (there's no language barrier whatsoever and they understand each other perfectly at all times) in less time than that, while being on crack and on other considerable hardships, too.