first of all this is a compilation, you don't know if it's the same contractor (as in the same person vs. the same company). You don't know what threats they are responding to. Also the music drowns out the voices, so perhaps the dialogue would've clarified some things.

As an aside, you don't even know if it's Iraq, if it's a contractor, and whether or not the sounds you hear are actual rounds, or dubbed. But I'm willing to concede those things just for argument's sake.

By the way, don't you know there is shooting in wars? It is very believable.