CES Letter Core Question
Does the fact that the witnesses were excommunicated weaken their testimony?
Within eight years, all of the Three Witnesses were excommunicated from the Church. This is what Joseph Smith said about them in 1838:
Such characters as...John Whitmer, David Whitmer, Oliver Cowdery, and Martin Harris, are too mean to mention; and we had liked to have forgotten them.
CES Letter, Page 102
If the experiences of the Book of Mormon witnesses were contrived, excommunicating them would have provided a logical motive for them to expose Joseph Smith. It is clear that their testimonies of the validity of their experiences transcended any devotion to Joseph Smith or the Church he founded.
That Joseph Smith would allow these men to be excommunicated demonstrates his confidence that the experiences of the Three and Eight Witnesses were real and that consequences for denying them would have been between them and God, not between them and himself.
After receiving their witnesses regarding the Book of Mormon, the men were not instantly holy or righteous. According to the printed testimonies, they were commissioned to bear witness of their experiences, but otherwise they were left to their own decisions and choices regarding future beliefs and actions.
John Whitmer, one of the Eight witnesses, was challenged about his decision to apostatize despite his testimony of seeing and handling the plates. He justified himself by saying that he did not have a witness of the Book of Mormon translation, having only handled the plates: “I cannot read it, and I do not know whether it is true or not.”
Hiram Page likewise told an excommunicated apostle that he was sticking to his testimony, despite his estrangement from the Church: “As to the Book of Mormon, it would be doing injustice to myself, and to the work of God of the last days, to say that I could know a thing to be true in 1830, and know the same thing to be false in 1847.” Click here
All the witnesses who left the Church (all Three Witnesses, and three of the Eight Witnesses) continued to affirm their testimony. Two of these six eventually returned; none recanted. Click here
CES Letter, Page 102
The author seems willing to accept any ad hominem. If this charge were true, why did Cowdery not blow the whistle on the whole scheme? But he didn’t—despite abuse from Sidney and being estranged from Joseph. This strengthens Cowdery’s witness.
 "Theodore Turley's Memorandums," Church Archives, handwriting of Thomas Bullock, who began clerking in late 1843; cited in Dan Vogel (editor), Early Mormon Documents (Salt Lake City, Signature Books, 1996–2003), 5 vols, 5:241.; see also with minor editing in Joseph Smith, History of The Church of Jesus Christ of Latter-day Saints, 7 volumes, edited by Brigham H. Roberts, (Salt Lake City: Deseret Book, 1957), 3:307–308.
 Letter of Hiram Page to William E. McLellin (30 May 1847), Ray County, Mo.; cited in Ensign of Liberty 1 (1848): 63.