I don't know, the more I watch it the more I get the idea that civilian population means close to nothing as long as the target is destroyed. The full version shows the other engagement against a building where they saw bunch of gunmen walk into. As they fire the Hellfire, there's clearly a guy walking by the building who seemed to me be just a civilian passing it on his way somewhere *KABOOM*, he dead.

(At around 34min to the full vid)
Now, I know there will always be civilian casualties in a war, but it would've taken less than a minute for the POSSIBLE civvy to get clear before shooting.