Half the town probably knew this detail, just takes one person to tell another and soon it spreads. I see no solid evidence Pankey committed this murder, only an ex wife's comments of his interest in the case and a clue about the crime that many probably knew from gossip.I just went back and re-listened to an episode with Norris’ interview to make sure I was remembering this right. He does mention it as well, so I agree I don’t think that can be used to show guilt.
This does not make him a murderer and I agree that Norris makes a better suspect.