My WAG is he did. I believe that from time to time, the DPRK has “need” of an American “hostage” or “prisoner” so to speak. I believe that it suits the propaganda purposes of the regime for the American to have actually committed an offense. Evidence? Aside from one exception, every other American we know (outside of military incidents) who has been detained in North Korea committed an offense.
The full list of Americans who entered North Korea and their known offense:
Evan Hunziker, Euna Lee, Laura Ling, Robert Park, Aijalon Gomes - All entered the DPRK illegally. There is no real contesting this, they all did it. The two female journalists who worked for Al Gore’s news channel (Lee and Ling) have equivocated on this a bit, as to whether they only briefly ran into North Korea and then back and were followed by DPRK guards, or whether they were actually apprehended in the DPRK, but they don’t really contest they crossed the border illegally. [If you’re wondering how this is possible–it’s not done across the DMZ, the rivers that separate North Korea from China freeze over often in winter, and can be walked across. There are certainly North Korean border guards about so it’s not easy to just walk in and walk out, but it’s not anything like the DMZ, you can definitely cross (either way) without being seen–but you run the risk of being caught. Most of the North Korean who have escaped the country have used this very route.]
Eddie Jun Yong-Su - This one we don’t know fully, because DPRK didn’t elaborate much in the press releases about him and neither him or his family has been very forthcoming. However it is believed by news sources that sometimes have information out of North Korea that while operating a business in North Korea he was performing illegal missionary work. It should be noted this isn’t atypical, a few other people have done this both of American and South Korean nationality. It’s difficult, but not impossible, for certain foreigners to be able to operate certain types of business in special regions or special industries in North Korea. It is one of the few ways anyone from the outside can get any access to “real” locals at all, and thus is an attractive route for the foolhardy secret missionaries. From what I can tell all of the individuals who have done this have either South Korean or Chinese citizenship (or like Yong-Su, have dual American and South Korean citizenship.)
Kenneth Bae - Essentially the same as Yong-Su, he set up a tour business in the DPRK and was using it to do missionary work. He hasn’t really denied this to my knowledge.
Matthew Miller - He traveled to North Korea intentionally to get arrested, so he could do some “subversive journalism.” Of course, as an American during his detention he had no contact with “normal” North Korean prisoners. He 100% admitted this was his plan when he was released and returned to the United States.
Jeffrey Fowle - Left a bible in a bathroom of a bar that was sometimes used by normal North Koreans (it was cleared out for his tour group.) While it’s possible he did this as an innocent mistake, not understanding what he was doing, when he made it back to the United States he explained himself fully. He said he knew what he was doing, did it intentionally to spread Christianity in North Korea, and he considered it “worth the cost” of being detained for six months.
Merrill Newman - This is the one who it appears genuinely did nothing overt. Other than, he was a Korean War veteran, and the DPRK’s intelligence services was able to determine his history while he was in the country and detained him over actions he was involved in during the Korean War. It’s not believed he did any of the blatantly and intentionally illegal things the other detainees did.
Right now there are two Americans held by North Korea, and we cannot ascertain what they actually did until they are released (and give interviews): Kim Dong Chul and Otto Warmbier. But at least from our history, it looks like the North Koreans generally do not “trump up” charges against Americans or detain them and them frame them for things. Maybe they would if they needed to, but I think it best serves their propaganda goals for the detentions to be for legitimate actions the individuals took. With a few thousand Americans visiting North Korea every year via the guided tours, they have plenty of opportunity to catch a few Americans breaking the law anytime they “need” a detainee. I suspect that a lot of the Americans who go over try to engage in secret missionary work (and most probably fail in even coming close to a “real” North Korean), and that often the North just ignores it, choosing to detain them when they have need of a detainee.
