Don't They Have Building Codes?

AP reports, "A NATO airstrike destroyed a mud brick home, killing four generations of an Afghan family...during a firefight between Western troops and militants, Afghan officials and relatives said Monday."

I have a few questions:

[1] What is a militant?

[2] Did the Western troops wear white cowboy hats?

[3] Why would anybody build a mud hut anywhere near a NATO airstrike?