I think we can safely say today's Gunwalker hearings

were both productive and probably caused- are causing- severe indigestion among a bunch of people.
Newell was asked about his relationship with Kevin O’Reilly, Director of North American Affairs of the National Security Council, and this was followed up shortly thereafter with his being questioned why he began one email correspondence with the words “You didn’t get these from me.” [UPDATE: A copy of this email is presented here.] Newell, who was chastised by multiple Committee members for being evasive, answered that he and O’Reilly were long-time friends, but he would admit no wrong-doing in why he wanted O’Reilly to keep his name secret as a source for disclosure about an investigation that allowed guns to “walk” to cartel criminals in Mexico.

The question becomes: Why is Newell’s communication with O’Reilly significant?

Rephrased: Why are ATF field office management communications about Fast and Furious with NSC’s North American Affairs Director significant?
Well,
The President, Vice President, Secretary of Defense, and Secretary of State are considered to be statutory attendees of NSC meetings, but they are also regularly joined by the Chairman of the Joint Chiefs of Staff, the Director of National Intelligence, the National Security Advisor, and other executive officials. The NSC conducts its meetings in the White House Situation Room, and the National Security Advisor’s presence in the West Wing provides the President with direct access to research, briefings, and intelligence related to all aspects of national security. During times of crisis, the National Security Advisor is also responsible for operating out of the Situation Room in order to provide the President and other members of the NSC with regular updates pertaining to the situation at hand.
Put bluntly: this makes AG Holder(at the VERY least) and the President denying they knew anything about this operation extremely difficult to believe. And, just to make this even more heartburn-inducing for some people,
What’s evident from today’s exchange is Issa’s committee has some degree of access to past Newell/O’Reilly email correspondence. How much is one question. Where following up on what they have will lead—and how high up—is another, and the most important one of all.

I still have to wonder if Obama gave any information on this to the Bradys when he assured them of his working 'below the radar' on gun control. Be interesting if it were shown that people in the CSGV knew about Gunwalker, wouldn't it?