What's stopping the kid from making a new account though? Knowing myself, I did similar things as a child especially since my parents were not very tech literate.
The law itself disagrees. It's quite explicit that the point is to not allow kids into chat rooms at all without parental consent. It does not mention anything about preventing kids from accidentally joining chat just that they are not the ones able to provide consent to allow chat.
I've made fake accounts for my kids where I lied about their age, in order to bypass certain restrictions. That's how screwed up our legislation is in this area.