Indeed, kudos to those hikers. Here's the pertinent part (to me) of the TrailJournals post:
A 40-degree bag at elevation in the Smokies in the early Spring. To me that's almost asking for trouble. Since we are often asked on here for advice about bags to take on the southern AT.He had crawled off the trail under some bushes and tried to stay warm with his 40 degree sleeping bag. At that point he was barely responding anymore.