Josiah looked up at his uncle - what? He didn't get what the problem was. Her protests were dumb, and all they were both trying to do was keep her safe -- and another one safe too, his mom from that other Roy's world. And it's not like his mother didn't constantly make excuses and try to downplay everything which didn't help anybody, right?
But that wasn't a very happy look and he knew better than to argue his point when grown-ups weren't happy about anything.