I don't know all the details, so I can't condone this or condemn this in one way or the other, aside from it looking bad on the face of things.
I will say from personal experience that there could be certain mitigating factors: There are no addresses or even a proper street system, so it's completely plausible that they showed up at a neighbor's house by mistake. Another option is that there were walls torn down or other building modifications done which would lead to the confusion.
As to the shooting itself, I know that during an arrest your senses are at the most alert, and more than once we've found folks sleeping with pistols and knives under their pillows. The ROE are very specific: Means to kill and intent = shoot towards center body mass to kill. This guy may have tried to do the wrong thing, or even did something trivial like turning on the light and one of the soldiers twitched.
Like I said, without more details, there's nothing else I can really give you.