He makes no mention of a stone in St. Paul's Cemetery.
You all are in agreement that the actual burial place of Paul Augustine Hebert is Robert's Cove, for the pension application of his widow states his burial place. There is a gravestone at Robert's Cove indicating that he served in the 28th Thomas' La. Infantry.
Click on the following link and scroll down toward the bottom of the page to read what he says about the stones.
http://members.tripod.com/carol_fus/paul_hebert.html
Best regards and much success in your work--