What is the legality behind referring specialist or other doctors?
Someone I know was initially diagnosed by doctor A who got my friend tested and got results. Doctor A then referred her to a specialist Doctor B who after consulting was now referred to Doctor C because Doctor B treatment isn't suited. All this referring incurring expensive out of pocket consultation fees. It feels very off and there's a lack of transparency.
Isn't Doctor A supposed to correctly assess the diagnostic and refer correctly to the correct specialist?
Medicine is highly specialised. If you want to be treated by someone who is an expert in the area, best to seek the right specialist. You can go public if you prefer (ie hospital clinics or places that bulk bill) which are free if you don't mind waiting a bit.