Factual error: In the opening sequence just before Minute 1, after the asteroid is reported to have hit Hamburg (Germany), it is shown in red how the mimics spread through Europe. But wrongly this spreading is originating from the center of Europe (somewhere in Austria) rather than in Hamburg (on the far north of Germany). You can even see in the next shot how it spreads from Austria to Germany, Czech Republic, Slovakia and Hungary, which makes no sense if the origin is supposed to be the far north of Germany. (00:00:55)
Factual error: At the beginning, when Cage and the general are looking at the map of the Europe, you can see that they've marked the capital of Croatia as Ljubljana, and not Zagreb.
Factual error: The dam where the Omega is supposed to be hidden first is identified as being located in Germany. In reality, it's the dam at Lai da Curnera in Switzerland. In the German dubbed version, it is correctly identified as being in Switzerland.
Factual error: Cage is a major in the Marine Corps. Majors don't have gold on the brims.
Answer: It must be either a piece of equipment that someone noticed was in the shot, and tried to move out of the way in time. Or some sort of reference marker for Tom Cruise to take a cue from and point his gun at.
Scott Benham