From what you describe, this fellow is distinctly not a star developer. Programming is a team sport, and those who do not play well with others do not add much value to a project.
Personally, I might not remember code I wrote 6 months or more ago, and very much value a history of the changes in some sort of Source Control.
If you had regular code reviews with this guy I think you would see that he's not as stellar of a developer as you think he is.
