Questioning the story is fine. Brigading isn't, and failing to actually attack the credibility of the reporting isn't.
Yes, the origin of the story is the Sun, but until there's a reason not to trust it, the fact-checking by other, less tabloid-y outlets that have also carried the story seems trustworthy.
The story is also well within the norm for the behavior of the North Korean dictatorship.
Do you have an actual reason to suspect the story is false? Post it here. I won't delete it if you credibly back your claims up.