I think a country like the DPRK needs to be very cautious in circumstances like this because there is a risk this is a ploy by the US to infiltrate the DPRK or use the situation to score some kind of propaganda "win". Though i would rate the former as rather unlikely since if they wanted to infiltrate the DPRK it would be much easier and much more effective to use South Koreans who aren't as conspicuous and who already speak the language. I agree with the last part for sure though. Under no circumstances should he be extradited to the US or any of their vassals (we saw what happened with Assange in the UK). If the investigation concludes that he is not a spy and his motivation is genuine then imo he should be given a choice whether to stay in the DPRK under some kind of supervision for a few years to make sure that he won't cause trouble and with a guardian to help him integrate, or whether he wants to go to China instead where he will probably have an easier time integrating since more people speak English and the lifestyle is closer to what he is used to.