CNN’s Jake Tapper had a certain advantage in his interview this afternoon with the Guardian’s Glenn Greenwald: He’d seen how peer David Gregory of NBC News has been shredded for his question to Greenwald on yesterday’s “Meet the Press.” Here’s how Gregory phrased his gotcha inquiry: “To the extent that you have aided and abetted Snowden, even in his current movements, why shouldn’t you, Mr. Greenwald, be charged with a crime?”

Greenwald clobbered Gregory for the “assumption” in his question.

Here’s how Tapper approached the same matter:

Fox News Channel’s James Rosen encouraged his leaker to give him documents and set up what he thought was a secret way to e-mail him. I’m not going to launch any accusations at you, Glenn, but did you do anything beyond what James Rosen did in terms of communication with Snowden? Did you work with him to get him a job at Booz Allen? Did you advise him on how to transfer the documents?

In response, Greenwald said that he’d bristled at previous such questions because he found “pernicious” the underlying “theory” that “if you’re a journalist and you work with your source and you cooperate with them in obtaining documents . . . that somehow that’s called ‘aiding and abetting.’ I call that investigative journalism.”

After he got that out of the way, Greenwald insisted he did “much, much less” than what Rosen did with the source for his June 2009 scoop on North Korea. “Anybody who wants to raise this insinuation against me, against The Washington Post, Bart Gellman or anybody else that we somehow ‘aided and abetted’ Mr. Snowden — anyone who wants to even raise that, let alone claim it, ought to be compelled to point to specifics or point to evidence to support that accusation, because there is none. Otherwise it’s just reckless insinuation and shouldn’t be tolerated,” said Greenwald.

Tapper’s invocation of the Rosen case makes sense as a benchmark. The famous search warrant affidavit in the James Rosen case — which sought access to the reporter’s personal e-mails — notes that Rosen at one point asked his source, State Department security adviser Stephen Jin-Woo Kim, for “internal memos” and “internal State Department analyses.” That same affidavit cited probable cause that Rosen had been an “aider and abettor and/or co-conspirator” in a violation of the Espionage Act.

In his case, Greenwald told Tapper that he “didn’t even know where Mr. Snowden worked or what his name was until after he was in Hong Kong with the documents.”