Joseph Fielding Smith teaches that not everything Church leaders say or write is inspired by God; teachings from leaders must be measured against the Standard Works of the Church.
Joseph Fielding Smith, Doctrines of Salvation, 3 vols. (Salt Lake City: Bookcraft, 1954), 1:322-23
ALL TEACHINGS MUST CONFORM TO REVELATIONS. It is not to be supposed from this that all that has been written outside of the standard works of the Church is discarded and rejected, for these things are profitable as helps in the government of the Church, and to promote faith in the members. The point is this, if in these books mistakes are found, "they are the mistakes of men," and the Church as an organization is not to be held accountable for them, but for that which is received from time to time by vote of the Church, as it comes through the President of the High Priesthood. When the Lord reveals his mind and will, it is to be received, "whether by mine own voice or by the voice of my servants, it is the same," but we are not to be judged by unauthorized sayings or deeds.
If I should say something which is contrary to that which is written and approved by the Church generally, no one is under obligation to accept it. Everything that I say and everything that any other person says must square itself with that which the Lord has revealed, or it should be rejected.