Counterterrorism expert who found Assange court filing: 'I just thought it was a typo'

But when someone sent him a Wall Street Journal story on the government's high hopes for prosecuting Assange, "I said, 'Don't I remember that name from somewhere?' " he told CNN on Friday.

The fact that he remembered it at all was surprising. Hughes is deputy director of the Program on Extremism at George Washington University, which studies the proliferation and prevention of violent extremism.

"We pull about 15,000 legal documents and track everybody who's ever thought about joining ISIS," he said, adding, "I myopically focus on terrorism -- unless I saw something that had the word 'ISIS' in it, I was going to gloss over it."

Hughes had been looking through court filings for unmarked search warrants, and the case caught his eye with several possible links to terrorism. One of the prosecutors listed had previously led a high-profile terrorism case and the defendant's father had been convicted on terrorism charges, so Hughes took a look.

"When I pulled it a few days ago, I saw the Assange nugget, but I didn't think anything of it," he said. "I just thought it was a typo -- everyone's busy, whatever."

But when Hughes was putting his son to bed Thursday night, someone texted him the Wall Street Journal story.

"So then I looked at the document again and I noticed there was an extradition in there," he said. "And then I tweeted it."

"You guys should read (Eastern District of Virginia) court filings more -- cheaper than a Journal subscription," Hughes joked in a tweet Friday with a picture of the filing, which stated that "no other procedure is likely to keep confidential the fact that Assange has been charged."

"I thought I'd make a joke to the Wall Street Journal reporters about their paywall," he said, having seen them a few weeks prior. "I've got to end up buying a subscription, I feel obligated now -- maybe I can get a discount as a professor."

Hughes wasn't surprised by the find, as his team encounters odd details in its court filing searches.

"For my job, we do a lot of work going through the federal court record. They'll find things about drug trafficking or bribery," he said. "If I find something that's woefully out of my lane, I just kick it to a reporter who covers it."

"This is probably the most interesting one I've found so far," he added. "Interesting to you guys, I guess, but not interesting to me."