Here is an excerpt from his email:

Yes this is another Stenacapha and not a carnivorous rhytidid.

Stenacapha ducani and S. hamiltoni are difficult to tell apart from photos (and sometimes difficult even from specimens) but although this may look extremely similar to the last one, this one is actually hamiltoni! One key difference between S. hamiltoni and S. ducani is the way the adult sculpture develops on the later whorls of the shell. On S. ducani the adult ribbing on the earlier whorls always becomes less prominent on the later whorls and I could see this starting to happen on your previous suspect, although it was sub-adult. This one has the ribs still quite prominent all the way around at over five whorls of growth. That rules out ducani and makes it hamiltoni. It is also just a slightly flatter, less chunky looking shell which is another difference that points to hamiltoni, although they do vary. It doesn't help that the two species will live together in the same habitat and may even be found munching from the same fungus or sheltering under the same log.