How does NATO determine who is insurgent and who is not?

On September 16th, 2012, AFP reported that NATO troops killed eight Afghan women in an airstrike. These women were on a mountainside collecting firewood for fuel in a small village in the Alingar district of the Laghman province.

According to the report, ISAF spokesman Lieutenant Colonel Hagen Messer said that the shooting happened at around 1:00 am (2030 GMT Saturday).

Considering Afghan society and especially Pashtun traditions, it is almost impossible to believe that they would let their women go out in middle of the night, in complete darkness to collect wood. Traditionally, it is immoral and against Pashtun culture to let their women go out, especially in the dark, for work.

Moreover, it makes the story murkier when it says the women were in the woods at 2:00AM because they cannot see in the dark. Usually, Afghans collect firewood and pile them next to their houses and huts and it is the men’s job not women’s job.

The AFP and New York Times (NYT claims the airstrike happened at 2:00AM midnight) reports which claim that these 8 women were collecting wood in the mountains in the middle of the night have prompted speculation that the house which was used by insurgents was attacked by a NATO airstrike. These women probably ran out from the house to hide in a safe place that was targeted by a NATO airstrike. Among 8 dead there were two children as well.

Yet, the question is if NATO troops cannot make the distinction between men and women, and children, how can they determine who is an insurgent and who is an innocent civilian?