that happened in a different timeline, where hinata was smashed to bits...
it was the teacher that probably killed sora, then hinata at the funeral, which caused hinata to go to the past ->
hinata changed the timeline by going to hokkaido, now we know maybe sora went to hokkaido and killed his parents in this new timeline -> sora is still alive and we know the teacher is probably dead instead.
we're in a timeline now where sora killed the teacher and is confessing everything to hinata. if that makes sense... ┑(￣Д ￣)┍ hope im right..
That's the optimistic view. I'm going with the interpretation it was sora who killed hinata and the other guy at the funeral in a different timeline. Even back then, they didn’t let hinata open the coffin, which was weird.
If that is true, sora cold blooded killed him with the painting frame until his brain was smacked out
And he still says "his precious friend"...?