When they chose to trust Hunter, even after he lied to them.
Joe and Norrie followed Hunter to the edge of the Dome, only to learn he’d been working with the government to dig up information on the egg. They were rightfully angry, but instead of casting Hunter out, they listened to him and still treated him with respect. Perhaps it was their faith in him that drove him to call off the military, or perhaps he was just tired of living a lie, but Hunter transformed himself from a threat to a great ally.
Whoever said people can’t change has clearly never been to Chester’s Mill.