The information mentioned comes from this website --
http://www.bjhughes.org/hardisonmil.html

With the exception of "Capt. S. L. Hardison", nearly all veterans mentioned belonged to Co. "H", 48th (Voorhies) Tennessee Regt., a company recruited in Maury County. It could be that Hardison led guerillas behind Federal lines in Tennessee and came south when the Army of Tennessee retreated in December 1864. He might then have been selected to lead one of the consolidated companies of Forrest's Tennessee Cavalry. This would have been the 11th, not the 17th Tennessee Cavalry. It would not be the first case I've seen of a guerilla with no other connection to the Confederate military being paroled as a Confederate officer.