Perhaps they have ways of ascertaining that the samples are solid before they get the official written assay report and as such, know that the area is worthy of being further explored in detail using the drill rig. We know they are not shooting in the dark.
Through all the prior testing, the eyeballing of the samples A N D perhaps using some sort of "field testing equipment", they already know that they should drill the area. IMO that is not beyond the realm of possibility but I do not expect the company to fess up and say they have a mini test lab of sorts or field testing capabilities. Whatcha think Longbomb?
Jerry