This happened with my peppermint shrimp, emerald crabs, and pom pom crabs. Each time, I could have sworn the creatures were dead.
The latest was when I happened to walk by my tank and was startled to see my $25 cleaner shrimp plastered to the side of an intake tube. Really had me worried until I saw him frolicking on the other side of the tank and realized it was just a molt.
So glad Sally is fine!!