Even though I don't doubt that he really did die, the first thing that came to mind when I heard this was that it's a hoax. A way for the US and other governments to get a foot in the door in North Korea. They don't like Kim Jong-un, and he doesn't jump through hoops for them. So play the emotional card (a man died after being imprisoned in the country, so human right people will be all over this) and find a few more reasons to bomb the place. Just like they've done with so many others...