Yeah I believe VICE got him into North Korea. That wasn't the first time they were there though.
I watched a VICE episode last night that had a journalist riding with a South Korean Pastor who smuggles North Koreans through China, Vietnam, and Laos to Thailand where they're finally granted asylum and sent to South Korea. Along that whole route, if they were to be caught they would have been sent back to North Korea where they would be killed and their families would be forced into labor camps that basically mine for the countries little natural resources. There would literally be generations of families in those mines.
It's pretty intense, but really interesting journalism. It's gritty, obviously, and it plays well on HBO.
Another doc about North Korea that's awesome is Inside North Korea on NatGeo or Netflix. It's insane.