It's for real this time. Gary is dead... no doubt about it. I'm not really sure what did him in. Does anyone know the average lifespan of a snail? I saw him floating around the tank, not really stuck to anything, slightly shriveled and thought it was odd. A few days later though, I found his shell empty (I have to assume Bob got his soft remains). So that's it for him.
It's been nice knowing you Gary! Rest in snail peace.