My understanding is that they were targeting a response between 100 and 150 meters deep. That point would be determined as a point in the plane of the conductor of greatest strength in the anomaly. The conductor would extend up and well as down (its not a bulls eye) dip as well. Move your drill 20 meters closer than where you thought the anomaly was and you hit it shallower.

There is also the possibility that there are parallel conductors that show up as a single conductor due to the resolution of the geophsics being used.

That said, geophysics doesn't typically give you a lot of accuarcy and if you see evidence that explains the conductor you are usually happy with your geophysical interpretation. Just the fact that they were prepared to drill it from the opposite direction if they missed with hole one sort of alludes to the imprecise nature of geophysics.

A similar shallow interception happened in the first couple of holes at E2 where they hit the anomaly/conductor high in the hole when they were shooting for a 100+ vertical intercept. It happens all the time and is one of the reaons exploration drilling often targets an anolmaly at various depths and along strike to make sure they have seen what the target mineralization was.

At the end of the day there may still be another target downhole. They will continue to drill through to where they thought the target was suppose to be and revised their thinking about the anomaly from there. In any field program one of the key jobs of the geologist is to constantly refine their thing based upon what they see in the field. E2 would be a good example of this.

... Been There