Its a pretty amazing recovery but doubt if that was by just...

Its a pretty amazing recovery but doubt if that was by just going through a jaw crusher , as that would only break the rock up to about the size you would use to make concrete builders mix (about 25 mm in diameter )
I would think the ore tested would have gone from a crusher through a ball mill to get it down to about 100 microns in size (0.10 mm ), and then extracted with a jig or centrifuge , And if you are going to put in a ball mill you may as we get the full enchilada and get 5 or 6 CIL tanks .

There is an alternative lower cost method of gold extraction from rock called heap leaching with that you can just crush the rock to about 20mm in diameter and then irrigate heaps of rock with cyanide and collect the pregnant solution of gold
A company on the ASX cavalier is in the process of doing that , they put out a scoping study recently explaining the process and cost , and St Ives use to do it below Kal many years ago they may still be doing it for all I know . The issue is the recoveries are still lower than with CIL , with such a high grade deposit would we be happy leaving 1 gram a tonne ($110) in the tailings ?
Still would be nice to see some column tests for heap leaching