it seems to me that the possibility this device does not in fact exist deserves more investigation than is given by the article.

for instance, if you assume for a second that this device doesn't actually exist, then the current russian response makes perfect sense... it would be in their best interest to neither confirm nor deny existence of of such a machine. i.e. the benefits of hesitation on the side of a potential enemy that believes the machine may exist far outweigh the dangers of accidentally ending the world (since there is no danger at all).