>>why do you think horizontal drilling would give better results... I don't see how they could get higher grades.<<

If a vein is 1 meter thick (top to bottom) and 10 meters wide, drilling vertically gives you a 1 meter intersection. Drilling horizontally gives you a 10 meter intersection. Same grade, but the implied amount of gold is 10x as large.

BTW, this is only a reply to your question, and is not meant to imply that I agree with the original post that said KXL purposefully drilled veins this way. That's a pretty serious charge. Also hard to believe, since most of the criticism of KXL's results have been that the veins are too thin. It's also something you should be able to tell by looking at the core, since the layers won't be perpendicular to the core length, or close to it.