Just based on experience, I'd view this as a transaction error. A clerk copying a long list of names from one sheet to another could easily make that kind of error. I know I could.
Language on paroles stipulated that the signee promised not take take up arms again until formally exchanged. Soldiers who surrendered at Vicksburg MS and Appomattox Courthouse VA signed paroles which they took home. Soldiers paroled at Vicksburg and later captured again at Chattanooga were 'red-flagged' by Federal authorities for violation of parole, the contention being that they these soldiers hadn't been properly exchanged.
Oath of allegiance is a different kind of document. That's the end of the line for a Confederate soldier, the document verifying that he would recognize no governmental authority other than the U.S. government. If caught under arms resisting government authority again, he could expect his remaining time on earth to be brief.
FYI, the Pledge of Allegiance was modeled on the Oath of Allegiance.