It wasn't made totally clear just what the 'muck' sampling was intended to be applied to. Let's face it they drove a round tunnel into the 'zone' and then took some samples from the ore taken out in this drifting operation, well muck from driving.

Personally I don't think you can take the sample and apply it to the area of mineralization which will be removed/mined because the shaft cut out will be a lot narrower than the access tunnel.

Here's simplified way it's done, they cut up following the mineralized areas. (drill holes/blast and let drop) Will follow up cutting/blasting as they go and minimize taking out rock that isn't mineralized. Get a small miner and you are well under a meter width (unless mineralized area is more than meter wide).

Now compare that one meter (or less width) with the 3 or 4 meter width of access ramp where a lot of the rock isn't mineralized. You'll see that that 3 or 4 grams per tonne changes into 12 to 20 grams awfullly fast.