The varying rules bothered me, so I just called the head of NH Marine Patrol. He said it is one of the most misunderstood issue he sees and admits many of his subordinates don't understand it. He said it is because it has changes 3 times over the last couple years.
The bottom line is that they do not distinguish between pull cord and self inflating so they consider all to be pull cord, thus making it legal if worn. It does not count if not worn since a pull cord won't float if not activated. Lessen learned!