Yes and the burl is usually from the area near a branch and also be from where you stated "down below" near the surface or even the roots. A lot of the fiddleback, birdseye, (not too common in walnut)and the various other names given to the re-arranged grain is caused by borers, virsuses, vines wrapping around the tree when young, etc., giving the wood a "fancy' grain.


David