Upgraded - My New (to me) 72 Gallon bowfront reef

[Joe Reefer]

Considering that pistol shrimp share/live in borrows with gobies I highly doubt they killed you fish.

[Whatigot]

only with shrimp gobies though, I have never heard of a clown goby hosting with a shrimp.
It's also not all pistol shrimp that form symbiotic relationships with gobies, some do not at all.
There are so many different kinds of pistols, even many that are unidentified, much like crabs.

The pet stores just generally only have the cave sharing kind as they sell well, if thats where you're getting your info...