When Idris Elba's character is drinking a beer from a bottle in the beginning of the movie, in the second shot you can clearly see he's almost finishing the beer, in the next shot it's half full.
When Zurab Radiani kills the governor with the straw fork, only two blades go through his throat. In the next shot, when he stabs the fork in the ground, all four blades are dripping blood.
In the final fight scene, Tyler enters the church with copious amounts of blood dripping from an active wound on his left arm. But as the final fight starts and progresses, no further blood appears from this wound.
When first at the cabin Tyler picks up two logs for the fire but in the immediate cut scene he is holding three.
Tyler's left cheek wound 's shape between shots.
The scene at the end when Zurab shoots at Nik at the church, Zurab should not have been able to fire a shot since his 1911 pistol was single action. He hadn't racked the slide back and the hammer was not cocked back.
The location of the gunshot wound on Tyler's neck would have completely severed the carotid artery and/or jugular vein, which would have caused him to bleed out long before he's rescued on the shore of the river.
One cannot wake up from coma just like Tyler did: he would have constantly been on sedative drugs putting him to sleep with the occasional scan or EEG or withdrawal of drugs under medical monitoring.
Tyler and Nik both use rifles with Eotech holographic sights and 3x magnifiers. These magnifiers are designed to flip to the side when shooting at short range, but in the movie they are always in front of the sight no matter the range. This would make indoor shooting very difficult, e.g. in the prison extraction sequence.
To minimize bleeding and pain, any fracture should be immobilized, not necessarily dressed as first shown.
An "open fracture" being dressed with so little care as to not mobilize the limb would have the kid screaming her lungs out.
In the beginning of the movie characters are driving in a full electric Volkswagen. When they leave off screen you hear the sound of a revving petrol engine.
When Chris Hemsworth's character shoots the helicopter with the mini-gun, he keeps moving the mini-gun even after the weapon stops shooting. (shortly before the helicopter crashes) This is most likely a post production mistake.
The view of the helicopter, just after Sandro says "He's coming' is visibly a shot in front of a green screen.
For an MRI brain to be done in the best technical conditions, the patient's head is put in a helmet/holder type of device.
When being attacked by prisoners in the initial extraction scene, Rake pulls out and fires a silenced Glock 17 and we hear a loud gunshot, not a silenced/suppressed one.
There is no state prison or a metallurgical factory in Tkachiri.
Aerial shots of Mestia, Georgia are on display when the title suggests "Kojori, Georgia".
After departing from Tkachiri, the train arrives to seaside station in a couple of minutes, but it takes roughly 90 minutes to reach seaside from Tkachiri by train.
In the train scene, Nik says she's unable to stop the locomotive because of the failed brakes. Normally, there are several independent brake systems, including emergency handbrake. There are also ways to slow down the train. Even stopping the engine and then reversing it would have been a safer option than simply bracing for impact at cruise speed.
Nik and Yaz did not know the prisoner was Tyler's sister in law.
Nik does her stitches herself in the plane instead of asking her brother. One hand is incapacitated, not even a good surgeon would chose not to get help.
Tyler does not worry the slightest when there is a car approaching as he is standing outside the cabin by the fire.
When they are on the plane, Yaz sets his phone down. The young man proceeds to pick up the phone and make a call... Super Secret agents, no lock code on the phone...
The doctors, paramedics, nurses do not offer Tyler stitching his gaping wound on his left cheek, making it more likely to get infected or bleed again.
The helicopters could have just attached the train from the front, from the beginning...