Randburg Drivers License

Good day, I took my daughter for her drivers license at the Randburg testing station. It was not her first time but she practiced a lot. She managed to pass the yard with flying colors and proceeded to the road. When she approached a yield sign she slowed down and made sure there is no traffic before she proceeded. She was then told she failed because she didn't stop completely!! The lady was very rude to start with and I'm not sure what concerns me the most, if she failed her on purpose or that she didn't know her road signs. I know nothing will probably come from this and it is not the first time I hear that people get failed on purpose at the Randburg test station. The test personal's word is final and there is nothing we can do about it....