The eagerness of the Apache helicopter crew to open fire is clear, and disturbing. But the contention that the journalists were with a group of non-combatant civilians may be incorrect. Take a look at this animated GIF:
Is that a camera? It doesn't look like a camera to me. I suppose it could be a tripod, but I think there is reasonable suspcion that it may be an RPG launcher. WikiLeaks has claimed on their resources page that a a camera was mistaken for an RPG launcher, and they've got a photo of said camera:
But even with a long lens, it doesn't look nearly as long as the the 3-foot to 4-foot thing in the picture.
I got this from a comment in this thread on hotair.com.
Note the characteristic diamond-shaped head that seems like a pretty close match to an RPG: RPG (Wikipedia Entry)
I'd also expect a tripod to swing a little differently, with most of the weight in the head, not the legs.
Here's another image:
It looks a lot like one of these (again, from WikiLeaks), doesn't it?
Notice the position of the strap, and thus the way it would swing if you were walking around with it hanging from your hand.
These seem to be from the original video at right around 3 minutes 40 seconds.
Here's a full-frame still (click to magnify).
Do you see an RPG, or not?
Here is a series of photos arguing that there was an RPG, and that the American convoy on the scene was at risk from it.
Here is an argument that it wasn't an RPG.
What do you think? It's a bit of a Rorschach test, isn't it?
Reports from the aftermath seem to claim that at least one RPG was found at the scene. But they do not seem to be from an independent source, and given the military's history of withholding information, and allegations of planting weapons at scenes like this, I'd like to see independent verification.
If the group was carrying at least one loaded RPG launcher, then we still have a tragedy, but the scenario looks a little different. An RPG is not a defensive weapon. A man carrying one wouldn't be a bodyguard to a journalist; he'd likely be an insurgent. The judgment of the journalists in choosing to "embed" with armed insurgents may legitimately be questioned. Ground troops in the area reported coming under RPG fire, and while the Apache helicopter was much too far away to be at risk from an RPG launcher, it was on the scene to support the ground troops.
I have not seen any evidence that I feel can justify the later shooting of the van, however.