It will be interesting to track the parallel cases of this shooting and the Fort Hood shooting.
At this time, Nidal Hasan's trial start has been delayed until June.
I'm not sure what would be improved for Afghan civilians by removing the United States from the picture. This happened just last Thursday, and far from uncommon.
U.N. civilian casualty report here. The executive summary (with charts) starts on page 1, some ways into the report.