The source for that info was his father. It may be true or it may be false.
If true, his dad may have unwittingly made Nick too naive to be wandering about Iraq on his own- in a war zone. And for whatever reasons Nick didn't play things conservatively or else he would have cleared his trip with State first and checked in with US forces on his own without having to be picked up by the police first.
That is, if the story is true that he was first detained by the Iraqi police.
Maybe things will become clear in time. But the story of the Japanese deliberately trying to get themselves taken hostage in order to get Japan to withdraw from the war does make me wonder about this story, too. There are still too many unanswered questions here.