I highly doubt American troops did not kill civilians. Wasnt there like over 100,000 civilians in Iraq that died like from somd kind of news i heard a year-ish ago? Forget, but i highly doubt American troops wont kill Iraq civilians (and may or may not give "oops" as an excuse ._.)
He means that we do not directly target them for the hell of it. (And for good reason. Thats the quickest way to lose a war.)