Just cause someone says something... Is irrelevant. I will conceed some leaders have said some things that aren't doctrine.
This is the whole point... Not everything uttered by a leader is doctrine.
Opinions are like armpits, almost everyone has a couple.
From the very beginning of the restoration we've been taught that not every word spoken by a leader is doctrine.
"A Prophet is not always a Prophet' only when he is acting as such." (Joseph Smith, Journal, 8 Feb. 1843, Joseph Smith Papers)
"What a pity it would be if we were led by one man to utter destruction! Are you afraid of this? I am more afraid that this people have so much confidence in their leaders that they will not inquire for themselves of God whether they are led by Him. I am fearful they settle down in a state of blind self-security, trusting their eternal destiny in the hands of their leaders with a reckless confidence that in itself would thwart the purposes of God in their salvation ... Let every man and woman know, by the whispering of the Spirit of God to themselves, whether their leaders are walking in the path the Lord dictates, or not." (Brigham Young, "Eternal Punishment, 'Mormonism,' Etc.," Journal of Discourses 9:150, 12 Jan. 1862)
"The question is, how shall we know when the things they have spoken were said as they were 'moved upon by the Holy Ghost'? ... I have given some thought to this question, and the answer thereto so far as I can determine, is: We can tell when the speakers are 'moved upon by the Holy Ghost' only when we, ourselves, are 'moved upon by the Holy Ghost.' ... In a way, this completely shifts the responsibility from them to us to determine when they so speak." (J. Reuben Clark Jr., "When Are Church Leaders' Words Entitled to Claim of Scripture?" Church News, 31 July 1954, p. 9, quoted in Teachings of the Living Prophets Student Manual)
"It makes no difference what is written or what anyone has said, if what has been said is in conflict with what the Lord has revealed, we can set it aside. My words, and the teachings of any other member of the Church, high or low, if they do not square with the revelations, we need not accept them. ... We have accepted the four standard works as the measuring yardsticks, or balances, by which we measure every man's doctrine. ... You cannot accept the books written by the authorities of the Church as standards in doctrine, only in so far as they accord with the revealed word in the standard works. ... Every man who writes is responsible, not the Church, for what he writes. If Joseph Fielding Smith writes something which is out of harmony with the revelations, then every member of the Church is duty bound to reject it." (Joseph Fielding Smith, Doctrines of Salvation 3:203-4, 1954-56; quoted in "Finding Answers to Gospel Questions," Teaching Seminary Preservice Readings Religion 370, 471, and 475)
"One of my good brethren years ago was on a Church board, and we were interviewing a young man who was doing some teaching that was contrary to the doctrines of the Church. The brother said to me, 'Why, he has his right to his opinion.' And I said, 'Yes, he has his right to his opinion, but he has no right to teach his opinion as doctrine in the Church.' ... I don't dare answer any of your questions unless I can find an answer in the standard works or in the authentic declarations of Presidents of the Church. ... All that we teach in this Church ought to be couched in the scriptures. ... If it is not in the standard works, you may well assume that it is speculation. It is man's own personal opinion, to put it another way; and if it contradicts what is in the scriptures, you may know by that same token that it is not true." (Harold B. Lee, "Restoration of the Gospel," 1954; "Using the Scriptures in Our Church Assignments," Improvement Era, Jan. 1969, p. 13; quoted in Teachings of Presidents of the Church: Harold B. Lee, chapter 7, 2011)