OK, new question, same theme:
Let's say that you fall a tree with a bit of a lean. The wood is extra-abrasive near the outside of the sapwood, perhaps to the point of throwing sparks. Further in, it gets very soft, until, popping the face out, you see that the center is hollow. You put the back cut in, and the tree comes down without major incident, aside from a chain that needs touched up. The wood visible on the stump is all sorts of different colors and textures, and the rot in the log looks to go at least five feet up the butt.
Is there any good reason to bother figuring out what caused the tree to be like this, or do you just buck it up and leave the butt as CWD? Is there anybody on the landing who is interested in knowing about this sort of thing, or is it a non-issue on the ground?