`Why could the inquiry not have been held in public with the sensitive parts held in camera?`
I think there are certain members of Government who consider all parts sensitive - perhaps especially those that relate to the manner in which the decisions was reached and on what evidence.
Also, perhaps the International Court at the Hague holds some Ministers (and ex-Ministers) in a hypnotic trance they may be prosecuted if there are less than `clean` documents which breach International Law to be revealed. But then the documents would have gone the way of certain expense claims; wouldn`t they???