Hmm, if you put Kefir into raw milk do you get just Kefir or a combo of Yogurt and Kefir?
Raw milk left alone will turn into yogurt it only needs a starter if you want to direct the flavor of the yogurt.
Does Kefir in raw milk do just that?
EDIT
Certainly would explain why Kefir tests so badly if made with pasteurized milk. See Breaking the Vicious Cycle for its failure: http://www.breakingtheviciouscycle.info