Bet the 9-11 Commission did not address this

Robert D. Chapman work in CIA for over 30 years. From 1957 to 1991 he worked on counter-terroism operations. In the Summer 1999 issue of the International Journal of Intelligence and Counterintelligence  he raised a problem faced by CIA in fighting terror groups:

Under U.S. law, if an agent commits a felony while being handled by a case officer, the officer himself faces the possibility of prison at Leavenworth or Marion. That was the law when I was operational, and I have heard nothing of its repeal.

Chapman also related this story about the role of congressional oversight in the Spring 2002 issue:

Back in the Cold War, a deep terrorist penetration agent reported that an (unidentified) commercial airliner was going to be hijacked. We knew if we blew the whistle, this valuable one-in-ten thousand agent would be blown sky-high. [and probably killed]

The agency decided that they would only intervene if an American citizen was on board. None were and the plane was hijacked.

Several years later a congressional oversight committee heard about the incident and reamed the agency until it hurt,

Going forward, the agency did not have the option to protect an agent in this way.  Which meant that it could not place or keep a source high up in a terrorist network. 

Yet now the preening politicians on the commission wonder why our HUMINT on Al Qaeda was so poor.