No, it's cool. He didn't care to listen to Rudeus's explanations. He apparently simply goes around killing anything Man-God related. However, Nanahoshi obviously made him reconsider that automatic action. Maybe time will tell why. If Nanahoshi is one of the very few people who can interact with Orsted without shaking in their boots all the time, it might explain why he listens to her. After all, killing Rudeus was nothing personal: He simply killed him because he was somehow connected to the Man-God. Thus healing him isn't a big deal either.

The incident will leave its mark on Rudeus, hopefully, but it definitely affected Eris. So, it wasn't wasted at all. Having some third party suddenly appear and be able to heal Rudeus, despite the huge, critical wound, would be a real deus ex machina development.