"The initial event was an IED. That's a provocation, even
if the response turns out to have been disproportionate,
or even unlawful."
Apocalypse Now II. Whether or not this is true, I'm sure seeing a buddy blown up every other day from cowardly IEDs, might tend to put one on heightened edge. Our soldiers are only human and under the circumstances, they are doing the best job they can do so we need to support them as best as we can, and give them the benefit of the doubt. This might be an occasion when one or two snapped, and his fellow platoon members decided to, mistakenly remain silent because they too understood and related to the frustration. It is hard to judge if you are not living it, day after day, cow after cow.
It also might be an occasion where true terrorists were firing at our guys and using the locals,or sympathizers, as human shields, what do you do in a situation like that?