Here is an interesting piece from Wired about the potential of command cover up and similar acrtivity in this set of cases.
I got to the Wired piece through this from congressmatters.com blog.
When bad news breaks it has become almost routine for those at the top to disavow all knowledge and let the hammer come down on those well down in the hierarchy. The pattern showed up again twice this week, and is now so common as to be almost standardized.