Since Brioude was not a bishopric, sacerdos loci quite certainly refers to the presbyter who was in charge of the basilica of Saint Julian.
Judging by the place of this passus in Gregory's narrative, this anonymous presbyter, most probably the one from the record [1969], was active around the same time, when Duke Sigivald was governing Auvergne in the name of King Theuderic I (ca 525–533).