I bitterly told people before the second war with Iraq that there were no WMDs. Any well read, educated, intelligent person should have been able to confidently say the same.
For example, a report about a new science result, the science is "one side." The "other side" is not the crystal healing quack that believes in magic. Two, you have video evidence of something along with multiple eye-witnesses. That is one side. The other side is not "oh but maybe all the witnesses are really part of a huge conspiracy and the video is fake!"
Some claims are not strong, and if a specific claim is not strong then you can explain why. But you cannot just flippantly say every story has two sides, that's bullshit. You need to say why a particular claim should be doubted.
You talk about science, yet, every anti-NK article sent in this thread are extremely poorly written and lack evidence to their claims. How is that "science"? Unless you are claiming that "science is when it matches my beliefs".
Again, the saying means that we as mere observers of huge, complicated geopolitical moves cannot know the full context and are vulnerable to propaganda. Yes even from the good(your) side. No conspiracy is required for that.
I have absolutely no doubt that North Korea is hell in earth, but there is a very very very good reason to say that every story has two sides. But maybe you just haven't experienced being the victim of "the reputable side" lying without any consequences. As a Muslim that grew up during the war on terror, I can't really say the same.