I have not yet found anything about that, but in this article https://charter97.org/ru/news/2016/5/15/204313/ they say that the mistake was due to NK fishermen that saw Korean text on the vessel and reported it. The NK authorities said to the Russians that we have to understand the action by the fishermen. Good to blame someone.
Very often it is possible to read some juicy details in the local Russian newspapers. We have to wait a few days.