Not that it is important to this thread, but I had a few broken noses during my childhood.
I used to be fairly angry. But there came a time in my life when I was about 16 where I was happy, and it didn't really matter. Let it go and live well.
As a small side note, it troubles me seeing him push his kid so hard into Karate. It is still influencing his decisions and impacting his child's life now too. (not that Karate is bad, but the reasons are)