I think someone should have had the discussion with Carlo about dialing back the retribution, but sadly it is too late. While Mike will need intensive medical care and months, if not years, of therapy, Carlo is lucky that Mike will most likely live.
Once the story comes out about what Mike did to Lance, and then the fight with with Travis, and the past history of Mike's bullying, Carlo will most likely won't be charged.
I'm not sad or sorry about what happened to Mike, I just think that in the moment it was overkill. The kick to the head was unnecessary and uncalled for. Mike was down on the ground, unable to defend himself. If it proves to be fatal, Carlo deserves whatever the legal system throws at him. I happen to think that at this point, Carlo isn't any better than Mike...