Will that section ever been updated? It seems to have been left fairly open ended, despite all the evidence to the countrary of his supposed identity.
1) We have evidence that he wasn't a Journey Man
a)His naiveity towards history
b)His attitude towards other Journeymen.
2) There is evidence that he isn't a fir'Bolg
a) The fir'Bolg don't seem to classify as a Civilized society. So why would they keep journals.
b) If they live in the woods, why would they have pumpkin farms and what not. Those things are what you would expect to find in a rural village.
c) The tone and way the narrator refers to the cities and civilization of man. He certainly would use a different inflection if he (a fir'Bolg, a race which seems to isolate itself in the Ermine and has been at odds with Man) were living far from his home.
2) We have evidence that he was a villager, and is human.
a) Prologue text
b) Peasant Text
c) His knowledge of human civilization. Considering the fir'Bolg are a race unto their own, why would they be so knowledgable about something outside of their lands and domain?