George...it IS a fine point, and one I've never seen contested- or even discussed.
I absolutely agree that the separate building needs a ground rod; lightning just might hit it, after all!
But, as I read the "25 ohm" requirement, that applies to the ground rod at the service drop, and every other ground rod- even on a seperate building- is a 'supplimental' rod for that requirement. I do not see a requirement for the "25 ohms" to be met for each and every rod, or structure.
How would you test it, anyway? I can't imagine you separating the two for testing, when they are required to be connected to each other.
