Hate to say it but I don't think you're right on the legalities even in the children's case. In the US anyway, in most jurisdictions [1], if the child's act was not malicious, then parental responsibility is not automatic, but is contingent on the result being foreseeable [2] by the parents.
[1] Hawaii and Louisiana are strange in this regard. Some other states have a version of this but severely cap the amounts.
[2] "foreseeable" here standing in for a broad set of legal standards that roughly map to negligence/gross negligence/recklessness on the part of the parent
"I don't think you're right on the legalities even in the children's case" almost certainly true :) I guess I'm wondering why we aren't seeing legal action for these events yet? are these not foreseeable?