South Korea skeptical of North's explanation of explosion?

Sorry to bring up the explosion mystery again...
from CNN, South Korean hydroelectric experts have doubts that the DPRK was telling the truth about the explosion last week. If it wasn't a hydroelectric plant, than the DPRK is hiding something, which is sure to add fuel to the fire of those who view the DPRK as a grave threat to international security.

I'm not trying to say the DPRK is or is not a threat, but how the next few months unfold should be interesting for the discussion of international diplomacy.

EDIT (9/17): Just an update to this story, which seems to get weirder by the day. South Korea now says there never was an explosion, the strange clouds were probably natural, and that the whole story was due to faulty intelligence. Read about it here.

Let us hope that any future "intelligence failures" regarding the DPRK won't seem so innocent. It seems that many people (myself included) were quick to jump to conclusions. It will probably be weeks before we know what really happened, if we ever find out at all, given the DPRK's secrecy.