Malicious compliance is a very fun concept that can even make you achieve great things, but it can also make you lose your job when done wrongly. With these stories, I sometimes feel as if the employees are looking for a way to get fired with cause instead of doing a cool comeback. It is one thing to do exactly what they asked you to prove some kind of point, and it's another thing to purposely mess up at your job just because you wanted to make a customer feel dumb. They may be dumb, but pointing it out is not a cool comeback. It's just reason enough to get fired.
The person in this story didn't get fired, and probably won't, which I'm glad, as I don't want anyone losing their job. But they should get reprimanded, as they drove the customer out of the business with their awful attitude. I, of course, do not agree with acting as the customer did. She was being disrespectful and pretending that the employees were assigned to a customer to follow around, which is insane. But to then, as an employee, bother the customer till they are tired of you and leave the store without buying anything is going too far. There is no reason to act like that when you are an adult. You are working. Behave as if you'd actually remember that.
Getting fired is, of course, not the solution. Here, this employee just needs to understand that work is not the place to be behaving like this, especially if you actually need your job. But this message is more to everyone who acts like this at work. Malicious compliance is a witty way to show that you were right all along, but it's also risky. Some bosses are not going to take it well the fact that they are being "played" by an employee. And others won't like the fact that you drove a customer out of the store, as it's losing business. So maybe cool it off with the malicious one and just comply with your job.