Factual error: The film is mostly set in Moldova. Early in the film, the general remarks at one point that insurgents are near the Russian border to the north. However Moldova does not border with Russia at any point in its geography. It only borders Ukraine and Romania.
Plot hole: It is stated that the "specters" are actually made up of Bose-Einstein Condensate, and that they are so exceedingly cold, they instantly kill whoever they touch, presumably via shock. This is all good and well, except that if they are so cold that they could instantly kill a person, there should be physical signs of their exceedingly low temperature around them or at very least on their victims. If nothing else, at least some frost buildup around them when they stop for more than a few moments or discoloration on the skin of the dead.