Charles W. Penrose teaches that no Church leader has ever claimed to be infallible.
Charles M. Penrose, “Editor’s Table,” Improvement Era 15, no. 11 (September 1912): 1045
Question 14: Do you believe that the President of the Church, when speaking to the Church in his official capacity is infallible?
Answer: We do not believe in the infallibility of man. When God reveals anything it is truth, and truth is infallible. No President of the Church has claimed infallibility.