There has been some dispute over the wound Chamberlain received at the Battle of Quaker Road (the bullet striking his left breast). For instance, Spear claimed that it never happened as he was with him the entire time. Even on videos of the American Battlefield Trust, one of the guides scoffed it off as ever happening. However, I stumbled across a primary source quote in which Chamberlain visited a Dr. in 1868 to address his primary groin wound. In that letter to his family, he mentioned how the Dr. also examined his chest where a bullet hit him in the left breast. In addition, there was an article printed in 1907 in which a visiting journalist described the field jacket that Chamberlain was wearing at the time and that he had, in fact, a bullet wound to the left breast.
So, if Chamberlain was not wounded in the left breast, why bother to mention that wound too in a casual letter to his sister? And, if that wound wasn't there, how did the journalist see it in the jacket when he visited the Chamberlain home in 1907? I suppose the point that I am getting at here is - Spear was certainly present (a primary source), yet obviously didn't see it happen (or lied about seeing it). General Wise of the Southern army acknowledged the wound during the surrender ceremony. So, even with primary sources like Chamberlain and/or Spear, it can be tough to determine. But, regarding the left breast wound, it more than likely did happen in my opinion. Getting sources from other leads, such as the everyday soldier as somebody previously mentioned above in this thread or from journalists in this case, I completely agree with and is crucial. In addition, the book by Dr. Rasbach on Chamberlain's wounding site at Petersburg does just that (utilizes other sources both North/South) to cross-examine the facts and it truly helps to gain greater insight into the truth as much as possible.
And lastly, regardless if the discussion is about the salute between Gordon and Chamberlain (or any of Chamberlain's wounds), one thing in particular that Chamberlain does throughout much of his works is to state that the experiences are not written as a true 'historian.' In other words, he wrote just as he experienced them at the time and writing from that deep sense of passion and emotion - not as a 'historian.' However, a lot of authors today take it as 'fact.' At the beginning of his book, 'The Passing of the Armies' for instance, Chamberlain candidly admits that those experiences are not without a form of coloring. If Gordon and Chamberlain did experience that special moment together during the surrender, it's not that he may have been purposely lying, but it was from Chamberlain's own interpretation from someone deep with emotion, passion, and of course being skilled with the pen and not always from a true professional 'historian' standpoint as he openly admits, which I can respect...