The historical development of clinical supervision has been variously interpreted in the international literature. Creditable evidence has accumulated, particularly over the past two decades, to show that clinical supervision has a positive demonstrable effect on supervisees. However, comparatively little research evidence has entered the public domain on any effect that clinical supervision might have on other nominated outcomes. In Australia, developments in clinical supervision were recently prompted by initiatives at national and state levels. Since 2010, lead agencies for these have sought feedback from professional bodies and organizations on a number of inter-related draft policy documents. The present article tracked changes over time between the draft and final versions of these documents in New South Wales, and reviewed the original sources of literature cited within them. The strength of evidence upon which the final published versions were reportedly predicated was scrutinized. Upon examination, claims to the wider benefits of clinical supervision were found to be unconvincingly supported, not least because the examples selected by the agencies from the international literature and cited in their respective documents were either silent, parsimonious, or contradictory. Many claims remain at the level of folklore/hypothetical propositions, therefore, and stay worthy of rigorous empirical testing and faithful public reporting. Such investigations have been acknowledged as notoriously difficult to conduct. The present article identified noteworthy examples in the contemporary literature that signpost robust ways forward for empirical outcomes-orientated research, the findings from which might strengthen the evidence base of future policy documents.