Being 100% charitable to Mr. Berger, this was remarkably boneheaded. Being less charitable, it was possibly criminal, and one has to ask what his motives possibly could have been. Daniel Drezner is willing to give him the benefit of the doubt (IE, that Mr. Berger was just plain stupid). The folks at Powerline and The National Review are far more suspicious.
Powerline posted a statement from House Speaker Dennis Hastert on the matter. The quote I found notable:
Mr. Berger has a lot of explaining to do. He was given access to these documents to assist the 9/11 Commission, not hide information from them. The American people and the 9/11 families don't want cover-ups when it comes to the War on Terror. They want the truth. And so does the U.S. House of Representatives.
Begging your pardon Mr. Speaker, but you led the charge against full accountability for 9/11 and against the 9/11 commission. So let's not get too self-righteous about the need for full disclosure.