I think it's much more likely that 1138 is another crazy clone who busted out somehow.
If he wasn't a product of the project cooked up to create a stable clone of Galen, then why would the original apprentice be given a designation like the clones being grown? If anything, wouldn't he be called Subject 1 or something?
"Grant Allen [...] had written a book about the Evolution of the Idea of God. [...] it would be much more interesting if God wrote a book about the evolution of the idea of Grant Allen." ~ G. K. Chesterton, The Everlasting Man