Crap happens. Especially elementary age kids like my son.
He gets aggressive because he’s a kid. He doesn’t understand that dealing with a trigger shouldn’t involve violence.
So I offer him between ways to deal with things. The incentive is that it gives him power over other kids. I teach him subtlety so that he ends up looking more mature.
I highlight the benefits for him and focus on that. I briefly go over consequences but show him that it’s a win win situation for him.
The situation in your case is being dealt with. It doesn’t get “fixed” overnight. You don’t need to apologize to the parents. It makes you look like you and your kid are defective.
This is a learning moment for you, your kid, AND the other parents. You realize it’s your moment and want to make sure you do it right. That speaks volumes about how good you are as a person.
The ball os in the court of the other parents. Pray they will learn and make as good choices as you have.