LITS-
This is probably where I show my age just a little. I entered the Marine Corps when Gen. Cushman was Commandant of the Corps. He always had a policy of speaking through the chain of command. If an event had occurred that needed to be addressed publically, he allowed the command at that location to speak for the Marine Corps. Granted, things have changed since then. For one, CNN and the 24 hour news cycle was not even thought of yet. I guess I have always believed that was the best policy.
I have no problem with Gen Casey speaking to the Army. In fact he should speak to the entire Army through the chain of command. But I do not feel that it was his place to speak publicly about what has transpired at Ft. Hood. I feel that it should have either been left up to the CG of Ft. Hood to speak on behalf of Ft. hood or it should be up to the US Army Senior Public Affairs officer to speak on behalf of the Army from Washington. If by chance those senior leaders felt that a more senior person should speak on behalf of the US Army, then let it be the Secretary of the Army as the Civilian Head. Personally there is a part of me feels that he (Gen. Casey) subrogated the media for the chain of command. Again, this is just a personal opinion only.
Hope that helps you understand where I am comming from. Oh, and I am not saying that that is the "right" policy.