I dont think anything should be about 'punishment' should it? What on earth does that achieve? Especially in the case of a child harming another child. Surely it should be about how to prevent it happening again.... jail time for a child is generally ridiculous, especially when as the article says he is from a middle class family who give a shit about him. Jail time usually only makes the criminality of a child like that worse. And a child assaulting another child is a psychological problem... punishment isnt going to fix it. You've got to look at what is actually going to be the best thing to do to sort the issue out. It cost a lot of money to hold people in prison... of theres absolutely no benefit to doing so the what is the point? Children who go into prison that young have a very high chance of reoffending... it should only be used as a last resort for very violent reoffenders.
I'm not okay if it is true that he has received zero consequences however. It needs to be showing up on his record. He should not be allowed to work with children ever.