I've seen that same phenomenon with Engelmann spruce, which has a spiral grain. Enormous splinters, 10 to 30 feet long, were driven way into the ground for at least 100 yards surrounding the tree. This was in the Colorado Rockies on a level plateau in relatively (for 10,000 feet elevation) thick forest--that just happened to be the one tree that developed the electrical charge. There was no way to tell if that tree had been taller than the surrounding forest.
The scariest thing was that this happened right along the trail we were following. We were horse packing, and one of the horses had her pack tip over, forcing us to stop, rebalance the pack and reload. It was while we were reloading the horse that the lightning struck. We got to the tree 20 minutes later, and realized that if that pack hadn't gone over, we'd have been right there when the lightning struck!
Awesome force, lightning, deserving of great respect. Ben Franklin was really lucky that he didn't get fried!