It begins with a theoretical premise that's not currently (if ever) testable.

Yes, and the infinite universe part of the premise isn't the only issue I take with this theory (actually the infinite universe theory is an interesting thought in and of itself: I have as much difficulty imagining a finite universe as I do an infinite one). Sill, I figured we'd had enough debates along these lines recently and decided it'd be more fun just to "roll with it."