I know this location well and this orchid in that location. Prasophyllum sphacelatum and Prasophyllum tadgellianum are very similar species found in similar areas and are not always easily separated from photos or even infield observance. I believe these are Prasophyllum tadgellianum rather than Prasophyllum sphacelatum which I find less common in that area. Now while knowing the flower size would help with P. sphacelatum being bigger than P. tadgellianum, these flowers are firstly crowded as are P. tadgellianum and the lateral sepals are fused with the tips free unlike P. sphacelatum where they are either fused or free. Which is a little more confusing. Another indicator of species is the free point of the leaf, which is not yet withered, as it would be if it was P. sphacelatum.