And had the doctor not done the tests and the girl had meningitis, the doctor would have been sued for not doing enough.
This is why we need a federal law to override all the common law that currently precludes parents from effectively waiving liability on behalf of their child. Under the current state of the law, there is no way anyone can avoid liability for injury to a minor child -- whether you're a doctor, a sports coach, or anyone else who ever deals with other people's children. It doesn't matter what the parents sign; the courts always rule that the parent can't sign away the child's right to sue. And the suit "by" the child is often brought by a social services agency on the child's behalf, even if the parents don't want to sue. This is the basis for the cases where doctors go to court to force a pregnant woman to have a Caesarian delivery against her will -- even if the woman signs a form saying she has been advised by the doctors that attempting a natural delivery poses a severe risk of death or permanent injury to the baby, "the baby" can still sue the doctors for everything they're worth if the doctors didn't pursue every available legal avenue to force the mother into a Caesarian.