What happened at Wanat?

Sen. Webb issued this statement yesterday afternoon about the different takes of the Army and Central Command on the battle of Wanat:

On July 9, 2009 I asked that the Department of Defense conduct an independent ‘re-investigation’ of the actions taken at Wanat at each level of command, rather than having the Army conduct an internal investigation. The Department of Defense concurred with this request.   

CENTCOM conducted an intensive, three-month independent investigation which concluded that the company, battalion and brigade commanders were ‘derelict in the performance of their duties through neglect or culpable inefficiency.’ General Petraeus approved this reinvestigation on January 21, 2010, and on June 23, the DOD Inspector General concurred with the findings as well.  As a result of these findings, the Army issued letters of reprimand to all three officers.   

However, the Army also conducted its own review of the independent investigation, resulting in the annulment of all three letters of reprimand. 

I find it deeply troubling that the Army has exonerated these officers and in the process rejected the findings of the independent review. This development raises concerns regarding the principle of command accountability in the Army."

Some time later, this statement arrived from the Army, and Webb’s ire became more understandable.