It would be better for Juha Bach to be just a title. But i think that Reesaroni nailed this one. Most likely the guy that got pwned is a mere clone, sent to discover Yama's Bankai. That way they can steal it, if they know the full power of it.
When other men blindly follow the truth remember:
Nothing is true!
When other men are limited by morality and law remember:
Everything is permitted!
We know the light...but when we shall create the dark?