I took that to refer to volumes that are just stored on a normal filesystem with their hidden bit set, or a dot prepended. If TCHunt could really find the "stored-in-free-space" Hidden volumes, it definitely would be able to distinguish them, or the disclaimer would at least read "TCHunt cannot differentiate between a deleted volume and a hidden one," because that's what it would look like--data in the filesystem without a corresponding inode/MFT entry. Plus, depending on whether or not it is trying to find these deleted volumes, its scanning algorithm would have to be completely different--one just following down the directory tree, the other working across the block device with a resizable window.
