N. Korea said about a week ago that, if U.S. does not respond to their suggestion, they will go their own way. I think this clash is part of 'going their own way' scenario. I have a feeling that this won't be the end. There will be more to come soon, if Chia Head sticks to his usual MO, in which he won't stop until he makes a big splash. If this provocation stirred panic among S. Korea and its allies, they won't need further provocation. However, these days, this one alone would not rattle anybody. So I expect there is more to come. They want to get inside the head of Zero, forcing him to cave.
Because already months ago, they had their temper tantrum, wanted to make Obama get the squirts, and abrogated their participation in the 1953 Armistace and all of those procedures set up for grievances.
If North Korea shows up at some UN sanctioned DPRK/ROK discussion over this, it will show they were just talk and never DID leave the Armistace Arrangement.