For what it's worth, many of the records of men of Company C, consist of one card, that being for a Receipt for Clothing in May, 1864.
Since there is no such card for him, which would signify his presence, he could at that time been hospitalized or perhaps on home furloughed.
Had he been captured we would expect to have seen a Union document. Since he survived the war, he did not die, nor had he deserted would be expect his widow's pension would have been denied.
Just some thoughts.