Neither Popes or Saints are, or need be, impeccable.
Then how does frogjerk (post #9) justify his quote of St. Thomas Aquinas?
(Quod 9, q. 16, contra 1) “In the church there is not able to be a damnable error. But it would be a damnable error if she would venerate a saint who was a sinner, because anyone knowing their sin, might believe the church to be false; and if this were to happen, they might be led into error. Therefore the church is not able to err in such things.”