I know that. I know he chose to die. I know that he probably would have killed me if I tried to use force to stop him. That doesn't change how I feel.

[But there's a little relief in his expression as Ryuunosuke starts to get it, at least. ...The ice has stopped spreading.]

We don't know why we come back to life, either. There's nothing saying that it will always work. Maybe only a certain amount of people can come back, or maybe it will just malfunction one day. It's a gamble.