Actually, no he didn’t. After rewatching the end when he tells her he doesn’t want to see her again, it does seem they explained more at that point. In the beginning however, it just seemed to come out of nowhere. “No! She’s still my mom!”. I just think there should have been maybe a moment of realization for him before screaming that. It seemed to come out of nowhere. He spent an entire season hating her, so I felt like we could have used that moment of “wait a minute…” before he starts screaming and calling her “Mom”.