I get where the woman is coming from, and they are still kids, but the old man is willfully trading compassion to keep the things he loves protected, and given that the kids' opening move was to bash him in the head, tie up and threaten them, it's not like he doesn't have a point. He also appears to recognize that Hasumi is a fucking psycho, and while there's other issues with presenting a child in that way, I think every reaction here makes sense and I'm glad it's being followed up on.