The listing you are looking at was compiled from "Confederate Roll of Honor: Known Confederate Dead, Vicksburg Campaign, January 1862-July 1863," by Gary W. Webster (1998). From the information given, it appears that it covers all known dead from all the units that were stationed at Vicksburg during that time period, and includes men from those units that may have died and/or been buried elsewhere. Since he died a year before the battle, and his records clearly state that he died in Buckatunna, on the other side of the state; I would surmise that he was furloughed home on sick leave and died there. There would be no reason, therefore, to expect that he would be buried at Vicksburg.