Walmart Employee Fired After Telling Customer They Shouldn’t Leave Their Dog Locked in a Hot Car

I understand customer service and that "the customer is always right."  However, I also understand the well being of a creature, so I am confused as to why a Walmart employee was fired after he told a customer that she shouldn't leave her pet in a hot car.

From her point of view she wasn't being rude, she just wanted to make sure the animal was safe. However, should she have been fired? If anything shouldn't there have been a write up or something.