Hey, I saw that episode. Actually I think that once a child hits a certain age (although I am not sure what that age is) the doctor doesn't have to tell the parents if the child comes in on their own.
Just like family planning. People under 18 can go there and they will not tell your parents. You can get, paps, aids tests, std tests, birth control, condoms, etc, without parental consent. So, maybe there is some kind of "law" included in the doctor/patient confidentiality thing that we don't know about!