If the NK missile happens to fall on a Japanese whaling boat, all will be forgiven.
Back during the big US/Soviet cold war build-up, both countries suffered tremendous setbacks when developing their respective ICBM programs. It wasn't uncommon, especially in the USSR, to lose complete control of these missiles. The Soviets had suffered many deaths during their development and testing changes.
Pieces of a PRNK ICBM landing on a fishing boat, or even a city because their mission control lost telemetry and rocket control is not a very far-fetched possibility. Every time NK test one of these longer ranged missiles, it's a crap shoot.