I've been fooled by a molting before ; / Mostly by my porcelain crabs....and a Calappa gallus I used to have, that was the worst. Such a neat guy.
In all honestly sorry to hear for your loss. It's nice to hear a person who can keep such an animal for such a long time, compared to other stories.
Calypso- Dont mix CBS with cleaners, usually CBS will be far more aggressive and will kill other shrimp. My CBS's were aggressive to everything, even me at feeding time. In a large tank like a 155 you can try it, but it would be a large risk imo.