Director of National Intelligence James Clapper has been getting beat up because he got embarrassed by Diane Sawyer when he admitted he had no clue about a 12-person counterterrorism arrest in the UK earlier the day of the interview.

In an interview with ABC’s Diane Sawyer, taped Monday afternoon, Clapper was asked about the arrests, which had happened hours before and were featured on all of the network morning news broadcasts. Secretary of Homeland Security Janet Napolitano and Chief Counterterrorism Advisor John Brennan, who were also participating in the joint interview, were aware of the arrests.

“First of all, London,” Sawyer began. “How serious is it? Any implication that it was coming here? … Director Clapper?”

“London?” Clapper said after a pause, before Brennan entered the conversation explaining the arrests.

Later in the interview, Sawyer returned to the subject.

“I was a little surprised you didn’t know about London,” Sawyer told Clapper.

“Oh, I’m sorry, I didn’t,” he replied.

As a threshold matter, it would be the intelligence community’s fault as a whole if Clapper should have been, but wasn’t, briefed about this arrest (the Administration has explained that Clapper was involved in START Treaty briefings all day Monday, and so didn’t get briefed), not Clapper alone. But I’m also wondering whether there’s more to his not getting briefed.

Note, first of all, that there are two kinds of briefings Clapper might have–but apparently didn’t–get: briefing about the investigation itself, and a briefing about the arrests, either before or after they happened.

Here’s some of what we know about the investigation and raid:

• The investigation, which has been going on for months, has been described as “intelligence-driven”
• Authorities triggered the raid after intercepted communications revealed the plotters were preparing to act
• Britian’s Home Secretary was told of the raids during the week of December 12 through 18
• Lord Alex Carlile, who acts as a watchdog on UK terrorism operations, also described watching one of the operations involved in the investigation
• The group has ties to a known (and banned) British radical Muslim group
• Like many of the recent arrests in the US, this group is alleged to have been influenced by Anwar al-Awlaki
• Muslim leaders in Cardiff tipped authorities off to a group of radicalized youth though MI5 seemed to already bee aware of the group; the group held a meeting two weeks ago attended by up to 30 people

Now, the Administration portrayed Clapper’s non-briefing as a Monday event. That is, they never suggested he should have known about the investigation before Monday.

I find that interesting for several reasons. First, GCHQ and NSA can work closely together to get coverage within their own countries, so it’s possible the NSA would have been involved in the surveillance process. And the allegation that these men followed Anwar al-Awlaki’s publications might further suggest US involvement in online surveillance (though I tend to distrust the Awlaki allegations as just the product of the Awlaki-villainization industry). There were no hints of international money transfers, but if there were, the US still has control over SWIFT-based investigations.

Then there are all the suggestions that this investigation has been going on some time, and the decision to arrest the men was made at least three days before the arrests.

In other words, it is at least possible the US had a role in this investigation, and it is possible the UK could have shared this information with the US intelligence community some time before Monday, when Clapper was too busy to be briefed on the arrest.

But he was so unaware of the impending arrests as to be taken totally by surprise, suggesting he, at least, had no such awareness of it.

Which leads me to wonder about two things. First, how long did John Brennan and Janet Napolitano know of the investigation? Did they keep the DNI out of the loop on preliminary reviews of the investigation? Before the Intelligence Authorization, ODNI was subject to FOIA in a way that CIA and other operational intelligence units are exempt, but that problem should have been fixed.

Remember, too, how badly burned the UK got in 2006 on their investigation of the liquid-based explosives. Facing mid-term elections and falling approval ratings, the Bush Administration wanted the Brits to trigger arrests earlier than they were prepared to do. To force the issue, Cheney sent Jose Rodriguez to Pakistan to arrest Rashid Rauf, a key contact of the plotters. Add to that US complaints after a British court released details on Binyam Mohamed’s torture. While I have every reason to believe the British and Americans still share intelligence information freely, I do wonder whether Clapper’s ignorance of this arrest reflect some limits on that sharing?

Now, maybe Clapper did have advance warning of these arrests. Or maybe he didn’t–and he was just too busy to be briefed on Monday.

But if there’s a failure here–or some limits on the sharing of information–then they’re more systemic than just Clapper and his immediate staff.

Though, it does all raise one question. As the Guardian reminds, Clapper’s the guy in charge of Obama’s intelligence briefings. So as interesting as the question of whether Clapper knew of the investigation and arrests is the question of whether Obama did.