Do they spit out the bad stuff once they've digested it? It's not infrequent that my new scoly, indophyllia, and acanthophyllia get some sand in with the mysis. I realize it's not a good big deal to spit out a big shell, but small sand?
Glad to see the LPS finally eating the critters that usually steal and maim the LPS! I bet the hermit was trying to steal some food out of its mouth and was in for a big surprise! My hermits are little vagrants and won't be replaced when they perish.
Apparently, elegance are even better at snailing than scolies are ... mine got one the other day, and I've read that one should expect something of a snail's graveyard to build up 'round an elegance.