What condition was the backpack found in, does anyone know? A backpack that had been placed there recently would be VERY different from one that had been stashed 5 months prior to being found.
I visited Kauai recently, and there's a very large camping population. We were told by one of them that we were wasting our money on a hotel - all you have to do, legally, to camp in a park is have possession of a fishing pole. Then, you can only stay for 2 weeks but if you move your tent site 15 yards, you're good for another 2 weeks. Free. Wild chickens are everywhere, and there's breadfruit and other natural foods. Very easy place to melt into the camping population, if that's what he's done.