Actually I understand that all this happened adjacent to an on-going firefight a few blocks away.

The assumption made was that these guys were either on their way to the action or supporting a flank etc, which tends to explain why when the Apache crew squinted at the camera they came back with "OMG RPG".

I absolutely don't condone what the U.S. forces did, but this is exactly the kind of inevitable accidental killings you get when you invade a country and I don't believe they are personally to blame for it. I blame those who sent them there.