Heh, like either side is some kinda saintly group of innocents.
Like it even matters, really. Iraqis and "Coalition" soldiers seem to be killing each other pretty indiscriminately these days, and both sides have done naughty things which in some ideal world aren't perfectly ordinary in a wartime situation. Truth is, our soldiers, being soldiers, are way too trigger-happy, and that anyone who's standing around throwing **** (grenades, rocks, whatever) at a bunch of trained killers carrying automatic weapons but doesn't make damn sure whatever they're throwing kills 'em on impact gets what's coming to them. There are a looot of stupid resistance fighters in that area, but using actual weaponry on soldiers in an open space, which would guarantee return fire, and not taking the five seconds required to make sure you're actually doing something strikes me as too dumb to be at all likely.
If he was throwing rocks, like all the protestors say, well, he's a moron, but at least one can kinda see how he wouldn't necessarily expect what came next, and hence not head for cover instantly or have an escape plan. As he got killed instantly, and didn't actually hurt anybody or even apparently come close (which the news services would certainly have reported on- they practically call it a guerilla attack every time somebody calls a policeman a nasty name out there right now), seems that that wasn't the case.
