80% of ORB's estimated deaths came from four central governorates (completely excluding 3 altogether), and the mortality responses in those areas had major internal inconsistencies. The conclusion of peer-reviewed critique is that the ORB mortality data were not credible.

That said, if someone is going to make a contentious claim, referencing the evidence or using some data to work up a basic attempt to substantiate the claim is the only to look like you aren't just making up claims.

If data just on deaths is varying by a whole factor of 10, I can't see how you could possibly get anywhere near any meaningful figure for 'combatant to civilian death ratios' in Iraq. You're adding another layer ontop of data that you already recognise is hugely flawed.

Add to that the issue that, in Gaza, Israel has completely sealed off the area from international observers, so credible data on "combatant to civilian death ratios" just won't exist.

All I can say is that based on the data, the claim made is absolutely not supported by the evidence. [Edit - even if the million figure were credible, it's still at least double, and actually indicating the opposite of what was claimed]