I agree, I wouldn't think a bnp would kill a snail I've kept these together in the past and never had any issues. I would think the snail has died naturally.
55 gallon elephant nose tank.
30 gallon borara merah and brigittae, shrimp and snails
70 gallon elephant nose tank, Gonzo the elephant nose and friends!
30gallon borara merah and brigittae green, red longfin bristlenose, shrimp, ninja, taiwan,bamboo, and snails.