One problematic quote that LDS tend to use (or some variation thereof) is "[the President of the Church] may err in the price of a horse, or a House and lot, but [not] in the revelations from God."
Why is this problematic? Well, the source is Orson Hyde, April 5,
1860, in defense of the Adam-God doctrine/theory, against Orson Pratt who
(correctly) rejected it as a doctrinal error:
Minutes
of the Meeting of the Council of the Twelve in Historian's upper room; Great
Salt Lake City; April 5. 1860 10 a.m. Present Elders O. Hyde, O. Pratt, J.
Taylor, W. Woodruff, G.A. Smith, C.C. Rich, F.D. Richards. O. Hyde . . . To
acknowledge that this is the Kingdom of God, and that there is a presiding
power, and to admit that he can advance incorrect doctrine, is to lay the ax at
the root of the tree Will He suffer his mouthpiece to go into error? No. He
would remove him, and place another there. bro. Brigham may err in the price of
a horse, or a House and lot, but in the revelations from God, where is the man
that has given thus saith the Lord when it was not so? I cannot find one
instance. (April 5, 1860, Minutes of Meeting at Historian's Office, Church
History Library)
Hopefully the quote and/or variations thereof will be retired as it is an example of support for something the Church would abandon.