Did that stop him being angry at her about tethering with Luke of all people? No, not really. He doesn't plan on denying that. But it isn't solely a sense of responsibility, nor solely his grandfather's instruction, that brought him out here, either. Whatever this is, it's happening because she chose to heal Vader--something he hadn't expected she would do. And also, it's her. Kylo has long trained himself to ignore the suffering of others, but she's an exception, angry or not.

"You were angry with me when you bandaged me up before." He's not entirely certain what had motivated her then, but he imagines there must have been similarities. She might have written it off with the excuse of practicality, but he remembers the way she nearly called him back when he left.