Continuity mistake: Ben Bart passed away earlier in the film but can be seen dancing on stage with the character Gertrude, at a James Brown concert where he is performing "I Got Soul (Super Bad) ". (01:46:00)
Suggested correction: During that sequence, they intercut James in his gold jumpsuit, with long hanging-down hair, and James in a black-and-white checked vest, doing the same song. In the black-and-white vest era, Ben Bart is still alive, so the dancing could have been from that era.
While that does seem to be the case, it should be pointed out that Ben Bart died in 1968, but the song James Brown is singing, "Super Bad", was recorded in 1970.
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.
Factual error: The helicopter flown is a Bell 407. The movie is set in '88 and the first flight of this type was 1994.
Plot hole: The main plot of the film involves Iris and Olson's mission: Destroying the Mobile Fortress 000. But Iris is a special gynoid. Her primary function is to activate the Mobile Fortress. The antagonist of this film could unleash calamity if he had Iris and the fortress. So, which idiot has sent Iris on this mission? The logical course was to send a demolition team, or better yet, send no-one at all. Anything is better than sending the activation key outside the safety of the Olympus.
Continuity mistake: Hercules and Tarak are sitting together talking and Hercules pulls out the necklace that his lover gave him as he reassures Tarak that he will get them to Greece. In one shot he is looking down at it in his hands, then the next shot his head is suddenly leaning back against Tarak. (00:37:45)
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.
Revealing mistake: At the end when April and Kyle are killed, they are thrown in a hole back first. When they are shown, they are neatly positioned beside each other. April even has her knees bent up and Kyle has his arm around her waist meaning they obviously positioned themselves for the final shot.
Factual error: About 20 minutes in, the group find a Welsh miners' group in the phone book. The character who is making the call speaks the first two digits of the phone number: "0, 1,..." The movie is set in 1984, when the dialling code for that district was "0639" In that year, "01" was the code for London, not Wales.
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.
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)
Continuity mistake: At the end we see Dermot bust into the courtroom with Buster in a chicken suit. However a few seconds later he is seen in the gallery wearing a blue shirt waiting for the verdict. (01:25:50)
Continuity mistake: After cutting through Black Manta's gun, Aquaman then slams Manta in the face with his trident and knocks him down. As he is twirling his trident in victory, you can see his belt and its design. But then it cuts to a close up of Aquaman and suddenly his belt changes in design with the bar in the middle disappearing and the black of his pants extending further up onto his orange shirt in the belt area. (00:03:50)
Factual error: Brian Wilson's panic attack on the airplane takes place circa 1964. However, the interior of the plane had distinctive sculpted doors on the overhead bins, a style first introduced in 1983 on the Boeing 757.
Continuity mistake: The sheriff wears his badge over his left side, which is traditional. As he is approaching on horse in the final scene of the movie it is still on his left side. Then for a few seconds in one shot his badge is on the right. (01:23:10)
Continuity mistake: Meghan is at the initial meeting with the TV execs. During the scene, the pens in front of the various board members change position between shots, and in the cut that follow her suggestive "hold them steady" hand-pumping, the woman with the light brown sweater is first with her hands off the table, then suddenly on it. (00:03:15)
Continuity mistake: Maddie and Taylor are talking about Maddie being over her previous fiance (that Taylor knows of). Taylor has the hair on her right side tucked into her jacket, but next time the camera is on her, her hair is neatly arranged over the shoulder. Similarly, her hair on the left shoulder changes position between shots just before Maddie drags her out to meet their plus-size friend. (00:06:20)
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.
Continuity mistake: The Judge and son are standing by the side of the road and there's a black bag on the ground between them. When they leave there is no bag on the ground.
Character mistake: When Mr. Rogue is spinning the globe to assign countries to the students he spins for Albert Morio, and he puts his finger just west of North America and says "Lebanon." Lebanon is in Asia, slightly northeast of Egypt and we can see Egypt on the globe on the other side of where his finger is at. He's nowhere near Lebanon.
Visible crew/equipment: In the scene after Petyr's death, Deacon is standing in front of a table and the window directly above the table is shown. At that point, you can see a boom mike being yanked out of sight. I know this is supposed to be a docudrama, but this is the only place equipment is shown in the entire movie.
Suggested correction: You said it yourself, it's the boom mic of the documentary crew. They make no attempts to hide the fact that it's a documentary.