Why can't people understand the difference betwen "innocent civilian" and "insurgent"?

As a brit who as served in Iraq and Afghan i understand how hard this is, we can not always tell all the ditails and thats when the problems start but thats the nature of fighting and insergant war, we have been doing it for over 30years in N Ireland but the biggest problem id the media they are far too quick to tell a story that shows every mistake or twisting every story to make it look bad as bad new sells as the Additional Details states the news will simply report "Soldiers opened fire on a house of prayer" without any further details... this has happend to me a few times and i knew the media would always report it badly