Those were unusual situations.
Auburn didn't need any kind of deniability with Chizik. No one else wanted him and no one really thought Auburn was serious about hiring him. Auburn just knew something apparently no one else did, like Duke did when they hired the basketball coach who'd just gone 9-17 at Army.
As for Bama, I don't think they even cared what people knew. They went after Rich Rod publicly, and then did the same with Saban.