He does seem like the kind of person that would sacrifice others for his own sake. However, Rin's conversion drew a lot of suspicion towards Sakura. If Sakura is an ordinary Communist, then it would have made more sense to sacrifice her since most of us are planning to vote for her right now. If she's an ally, the Inhibitor, or the Scanner, then it might not, since having Yomiel use his ability on an ally would immediately draw immense suspicion towards Paul, and the Inhibitor and Scanner are still useful.