I heard the story that there have been some heated discussions among N. Korean senior military figures on their rocket's capability. Apparently, they weren't entirely sure that it will fly.
Very interesting (about the 'senior military figures'). This is just a guess, but 40 seconds is actually pretty good for a first shot out of the box. Don't think the first stage would have been expended by then, though, so they likely aren't past the multi-stage handoff part yet -- a significant milestone.