Other mistake: In the scene with the crashed escape pod, everything inside is upended with books and stuff strewn everywhere. Yet there is a bottle of Vodka sitting perfectly upright on the bar in the background.
Other mistake: After John kills the Crypt Eater master, the camera quickly zooms away through the grave yard. You can see two graves close together have the exact same tombstone bearing the name Anthony Miller, born 1955. (00:48:50)
Other mistake: When Alice pushes in the new magazine, she doesn't pull back on the slide, meaning the gun doesn't have a new bullet in the chamber, thus is unable to shoot.
Other mistake: At the end, we learn that the predators are escaped patients from a hospital, ostensibly horribly mutated survivors of the accident. But if they've "escaped" into Pripyat, the hospital must be located inside the exclusion zone, and why in the world would they use a hospital there? All patients and staff were evacuated from the Pripyat hospital on April 29th 1986.
Suggested correction: The exclusion zone is only 30km. A hospital could have been built or other structure repurposed outside of the EZ. Simply walking at a normal pace, one can easily traverse 30km in a single day. Also, it's not an actual hospital that treats sick people. It's a clandestine operation to perform experiments on these mutated individuals.
Other mistake: When Steve, wearing his improvised shark cage, heads underwater to turn off a relay to prevent the others from being electrocuted by a falling wire, he is shown breathing through a snorkel taped to several metres of hose, open at the surface end. In reality, human lungs can't expand enough to pull fresh air through more than a couple of feet of hose. That's why diving hookahs use an air pump to feed air from the surface to the regulator mouthpiece.
Other mistake: The news anchor in the opening scene noticeably flubs her lines at one point.
Other mistake: Aladdin slices off one head of the monster in the tomb. The body spurts copious amounts of blood and the severed head even bounces on him repeatedly, but Aladdin's shirt is immaculate afterwards. (00:04:40)
Other mistake: Throughout the saga, blood has been shown as essential for vampire's healing factor, and Selene herself used her blood to heal people. Somehow, this time around neither her or her pal David think in any way of this basic fact, making a complicated trip to the vampire doctor necessary, who simply feeds the vampire kid some blood, the very first thing any vampire would do to regain strength.
Other mistake: After the daughter visited with her mother for the first time, she is reviewing the footage with the priests. No such camera angles were taken for what they reviewed, only an overhead room camera would have been available.
Other mistake: When Curt crashes into the force field when he is trying to jump the gap on his dirt bike, his point of impact is ridiculously high up. (00:59:40)