To date, I have located 9 accounts of the "Skirmish at Island Mound." 7 of the accounts are from a "pro- Union" point of view while 2 are of a "pro-Southern" point of view. Naturally, the "pro-Union" and the "pro-Southern" accounts are at odds with each other, and even amongst the 7 "pro-Union" accounts no two recount the engagement in exactly the same way. I call this the "traffic accident witness effect" where it is not uncommon for witnesses of the same event to recount very different versions of what they have witnessed. Nevertheless, by digesting all of the accounts with a very large grain of salt one can arrive at a very probable scenario for how the engagement unfolded. I say probably for until time travel is perfected, we may never know exactly how events in history transpired.
I have made available for you to conduct your own analysis of the "Skirmish at Island Mound" 3 "pro-Union" accounts and 2 "pro-Southern" accounts. You can view these as either an "html" document or a "pdf" document. Enjoy!
Captain Richard G. Ward's report dated Oct. 29, 1862 [O.R. Series I, Volume LIII p455-459]
New York Times [Moore, Frank, ed. The Rebellion Record, Vol. 6, Documents (New York: G.P. Putnam, 1863) p52-54]
Kansas "Journal" Account November 1, 1862 [Moore, Frank, ed. The Rebellion Record, Vol. 6, Documents (New York: G.P. Putnam, 1863) p52-54]
"The Battle of Fort Toothman" Old Settlers' History of Bates County, Missouri (Amsterdam, Mo: Tathwell & Maxey, 1897) 187-188 [both accounts are here]