People who go into a pet store care about animals. They're going to point out issues if they care. An employee should treat every customer like they're important and valuable. That's how I feel about it.
My family has been in the restaurant business my whole life and if there's one thing that was drilled into me, it's that the customer is always right. No matter what. Even if she was internally rolling her eyes and thought Abby was a crazy person, she should take the fish and see to it. We, as customers, should never
be given the idea that the employee of the store isn't taking the care of their stock seriously. Instead, all she did was lose a customer and make herself look immature. It's not personal. It's business. It's her job.