Did he apply on the Koryo Tours website?
You can contact Drew on twitter if you're curious about more details. Though, I imagine he would also recommend against visiting there any time soon. The situation in North Korea at the moment is a particularly volatile one.
He landed in China where he was then stowed away in a dud torpedo and slid in under their noses. After three days sliding up the Bukhan river in his scuba gear, he was found in a fast flood place soaking wet, still in his gear.
Luckily, the abstractness of the situation led to the authorities moving him into the least abstract place to see a westerner in scuba gear in North Korea. On a coach.
He failed to complete his top secret mission, but he broke a few hearts along the way.
I don't remember the details. But North Korea (at least used to) allowed an extremely limited amount of foreigners to visit the country every year. I think the number is even as low as 100 or so. But he didn't get to just go out and do whatever. It was a very controlled experience for him. Government officials escorted him everywhere and only showed him the country's best elements. Even if they still allow limited Americans in, probably not a great time to go.