Alastair Mackay has a post-publication peer review of the Lancet study on excess Iraqi civilian deaths from last fall.

When the survey was first released I was suspicious of it’s timing, but like all press releases in an election cycle, that taint goes with the territory. However trying to gather statistical information in a war zone is an inherently flawed concept, as is the concept of excessive deaths.
Genghis Kahn wiped out entire villages in horrible ways in order to instill fear in the town and villages yet to be visited. A case can be made that these excessive terror deaths saved many lives since whole populations surrendered rather than face a similar fate.
The determination of the defense is as much factor in the casualty count as is the veracity of the attacker. If I am willing to herd people trapped in a conflict into my enemy’s kill zone, I give them little choice but to kill them in order to attack me. I have greatly added to the excessive deaths number without firing a shot. This is particularly true in this war where precision weapons are particularly lethal in their localized detonation area.