One might also consider that his widow & relatives were not aware of his death until after the war. No claims to a nonexistent
government now.

Civil War Documents were folded two to three times, most likely to fit in Pigeon hold desk cabinets.

The paper quality in many cases was poor. Over time, ink ran, holes developed in folded corners as the document aged and was subject to usage.
Transcriptional errors in these documents abound.

In some cases, clerks taking names given them verbally, misspelled. All kinds of ways for errors to creep in.

In the case of my ggranduncle, a Private in the 43rd Tenn., who died at Vicksburg, is recorded in the cemetery list as a member of the 48th Tenn.