The problem is the people we fought did everything they could to look like civilians. They would carry trash bags full of bombs, and dress like women to hide weapons under loosely fitting clothing. This has the obvious effect of causing Americans to suspect normal, everyday activities as terrorist operations. Add to that the facts that things are hard to see at engagement distance and a failure to engage the enemy effectively will result in greater casualties on our side, and it's a recipe for misidentification.
It turns out the woman I almost killed was "washing" her dishes in a pothole of a road after a rainstorm. I had never seen someone do that before and her dish was a large metal bowl that resembled a common type of armor piercing IED. I don't know why I didn't kill her. I can't imagine the regret I would feel had I taken her life.