I am not a fan of the Norks, but the article said that they discovered a piece of rock with the words "unicorn lair" carved in it. That is not the same as the Norks claiming that they have found unicorns.
For all we know, there is a piece of rock with those words carved in it. People have been carving fiction in rocks ever since there were people and rocks.
Now if they found the ashes of a burned bush nearby........