So how did this come together and why did they send Bill Clinton instead of say someone actually serving in the US Government- like maybe his wife? Or would that be considered negotiating with terrorists?
And was it a US sanctioned trip or did Bill do it on his own? Either way, good work!
Unofficially, this was probably backed by the US government and Bill appeared in their stead. Officially the US government had nothing to do with the release of the two prisoners.
It's a tricky situation. They couldn't send someone with an official government position because that would mean that they would be officially negotiating with NK, an unacceptable alternative. On the other hand they could send someone with a lot of credibility, such as Bill Clinton. He might or might not have told Kim Jong-il that he represented the government, but that is of little concern when he's not officially employed by it and the government itself made statements in the media that they hadn't condoned the hostage negotations and in no way had sent any messages regarding this through Clinton.
In short, the way this was handled was ideal. NK doesn't lose face by giving in to a former US president (particularly since he probably apologized for the journalists' "criminal actions" which would be an admission of guilt in NK's eyes) and the US doesn't lose face by negotiating officially. Both sides are happy.