Ann: Spectacular new high-grade gold intercepts up to 1,093g/t, page-42

May be something to do with nugget effect , even a small speck of gold in a very small fire assay sample can disproportionately elevate the grade given one millionth of a tonne is one gram and they are probably only assaying 50 grams of ore at a time not one tonne of ore so the nugget effect is amplified by 20,000 times

There is something called core smearing to which misrepresents higher the grade .
personally I would calculate the cut grade for resource purposes and then down grade even that for a reserve due to dilution ,

But yes over enough population you would think the nugget effect would reduce .