The Cashier
Some people dismissed that idea, but they provided their own. Others believed that the extra charge was set up by the cashier in order to be able to pocket the extra money for themselves. The idea was that the cashier would be able to take the money out of the cash register after the customer had left. However, this theory may have several loop holes because a cashier should not have any type of permission to change anything in the computer system.

The Cashier
Unless that certain cashier has IT support backing up all her evil schemes. However, if you come to think of it, a million-dollar company should need to have a centralized computer system that cannot be easily used for deceit.
Passing The Blame
Although it seemed like a plausible excuse to blame the cashier, others weren’t buying it. Some critics claimed that it would be a lot easier to mislead the public’s attention and anger to a “single cashier” than have to face the idea of a major issue inside Walmart’s business model. After all, it is easier to fire one employee than get sued by the public. Walmart would get so much loss if that were the case.

Passing The Blame
Even if the fired employee sued Walmart for the lack of due process, they could still setup a financial arrangement for him to make him sign an NDA. So it is safe to say that Sharon was not aiming to get the employee fired. She wanted to expose the company for its wrongdoings if there were any.