This is sad, and hopefully doesn't happen in any similar cases.
Just because a person does not pick up a weapon for or openly declare to be an enemy combatant, does not mean that they aren't one. The article states that the observed "civilians" were helping the group shooting at our soldiers. That makes them enemy combatants, not civilians.
Now I do agree that civilian casualties should be kept to a minimum during war. However, that should not mean that we unnecessarily risk our soldiers' lives to keep from killing civilians who are not just in the way, but aiding the enemy. As was stated earlier, losing the support of the people may lose the war, but losing the support of the soldiers (or potential future soldiers) definitely will.
A couple of other things to keep in mind:
-Losing a good, experienced soldier because someone is afraid of killing civilians in the hostile area is not an effective way to keep body counts low. Experienced soldiers are likely to save more innocent lives the longer they live and do more killing of people-who-have-no-problem-killing-innocents. Keep in mind, the people that we are fighting have few problems with killing innocent people, whether its because they were in the wrong place at the wrong time or on purpose. The more of this type of people we are able to kill, the fewer innocent lives that are put in jeopardy.
-Soldiers who feel that their lives are less important than the lives of civilians who happen to be in hostile areas, especially when they know said civilians are aiding the enemy, are not going to be as effective soldiers as they could be. This particular problem would not only affect the morale of the current soldiers, but could also detrimentally impact the recruitment of future soldiers. How many people (and what kind) would really want to join if they thought that their lives were less important than the lives of civilians who are aiding the enemy or even just those civilians who might happen to be in the area where a conflict between us and the insurgents starts.