I'd go with 10-8, because Lopez wasn't firing back until the very end of the rd. But Lopez, slipped ,blocked, and rode with the vast majority of the punches Molina threw at him. So I wouldn't argue if someone gave it a 10-9. Lopez was clearly in control of himself though he did get hurt by a few of Molina's punches.
Good thread question! I definitely had it 10-8. If you want to see some 10-8 rounds without a knock down watch Holmes and Cobb