As the answer is having obsessive-compulsive traits it means that there is not enough information to make a diagnosis and based on the existing information those traits do not majorly negatively affect the student's life so the person is, based on known information, most likely healthy apart from some possibly more or less disorderly traits. The diagnostic process requires doctors to use actually most fitting answer as even though it doesn't necessarily mean that is the diagnosis, diagnostic criteria need to be filled even though they are not 100% specific. Evaluation of diagnostic criteria happens every couple of years where they will try to get more specific and sensitive. But that is a lot more involved process than one person changing their opinion of the criteria they use. In medicine, especially physical medicine, you can't always wait for an iron-clad diagnosis and sometimes you can't make iron-clad diagnosis even with the best testing available. Medicine is almost as much art as it is science and for a good reason. And it really is far from finished. In both the science part, medical ethics and biases in medicine are being developed all the time. Art part can be taught but only through experience.

Is it perfect, no. But there are also reasons behind why the question is put like this.