Oh nevermind, I guess there was an internal investigation and we didn't do anything wrong. I skimmed past that in the second article. Still, I don't see any accounts that suggest that they were in the middle of a firefight... sounds like there was an exchange of gunfire, and the minibus stopped to pick up wounded, and was then fired on as it was leaving.
But I suppose we shouldn't jump to any conclusions - until we know just how wounded these Iraqis look, and if the wounded were the same ones exchanging fire, it sounds like acceptable losses to me