Yino wasn't as righteous as Yunjin imagined.
After saving Yunjin, he chose to return to the battlefield for two reasons:
1- Yino wanted to test out the effects of the Mother Goddess of Life's [Blood and Bone Tempering] blessing that he had just received through the sacrifice.
Back at Ranmo Peak, Yuyan had already mentioned that she would be going to the Northern Snow Mountains. So with the battle at the camp turning into a bloodbath, the thick stench of blood in the air would inevitably attract Yuyan who was nearby.
Therefore, Yino timed his actions based on when Yuyan was about to arrive. This way, he could take advantage of the chaos to fish in troubled waters without fear of truly encountering any danger if he slipped up.
This was also precisely why Yino had promptly acted to save Yunjin earlier.
