From the story above. Not surprising that there is conflicting information on this. I tend to believe that it came from a tip, from JAG himself. It just seem to be too coincidental coming so soon after the arrest and the fact that this place seems so remote.
I agree, that would be too coincidental for the hiker to find the body at this time, but stranger things have happened.
Maybe the lead came from someone else and not JAG? I think about the only thing they could entice him with is say they won't go for the death penalty for the Chelsey's case, and I really hope this isn't the case.