Eamonn McCann compares Samarra with Bloody Sunday in yesterday's Belfast Telegraph.
I don't think the comparison is apt, primarily because there is no civil authority in Iraq. Secondly, from McCann's perspective, the Bloody Sunday protest was organized and peaceful. Samarra was not an organized peaceful protest, but rather an attack on US troops by Ba'athists using Iraqi civilians as cover. (I haven't seen anything that disputes this.)
Even if the troops reacted badly, it is not a comparable situation to Bloody Sunday. And, as it now seems, the numbers killed were not as high as first reported. I do think the army would do well to consider the audience (both Iraqis and American and other civilians around the world) before issuing these reports. The media will keep digging, so it's better to err on the side of caution. If you don't know, don't be afraid to say "I don't know". The army prevented the Ba'athists from interfering with the cash delivery that was the focus of that mission on the day. Therefore, mission accomplished - enough said.
Here's another post from a blog about the problems with "body count math". {Thanks to Mike.}