11.85 grams per ton is a very respectable concentration and there are dozens of gold mining companies in the world subsiding on far less. You are right that it is a small sample (worst case scenario, a highly localized deposit that contains ~1000 troy ounces of gold), however, if you look at the map, you’ll see that it is found on the edge of the site, with no other holes in proximity.
They saw gold 550 feet below the surface and 200 feet west of the spot labelled “RES10-59,60,61”.
Hole 60 saw gold, most other holes weren’t deep enough. It looks like only 52 and 54 had any real chance of finding gold, if it’s in that general area, more than 500 ft. below the surficae.