And as I tried to convey, we don't know the origin of the space object, though, the 13 th Tribe is a good guess, since the Cylons didn't know what it was; one would assume their superior "computer like" memory would include it were it one of their technology;
We don't know if it was "infected" by the makers, intentionally so, and left for the Cylons specifically;
We don't know if it became "infected" later, by some other means, by accident or on purpose;
We don't actually know that it does not affect Humans. We do know it DOES affect Cylons, and they guessed Humans may be immune, but so far the only Human exposure has been to Baltar, and that limited by his p-suit.
Interesting possibility: that the disease afflicts both Humans and Cylons, but not the hybrid Hera. Then, only she could save both species ...............
But back to the major question this "infected device" asks us:
IF it was left by the Humans of the 13 th Tribe, and IF they infected it on purpose, what does this tell us about WHEN the Cylons were created, and WHY the 13 th Tribe left the others?
Again, my thinking was, the Lost Tribe never had any cylons. If they created a disease to kill them, I guessed wrong on that one.