The Ethical standard of Confidentiality is one that demands an individual keeps information about a person or company out of public knowledge. It means that any information you have about a client or company that you work for is strictly meant to be between you and the company; no third parties. Information such as health details, company earnings, therapy session details, etc are examples of information meant to be kept confidential. A failure to keep confidentiality can result in legal action being taken against the erring individual.
According to the situation that has been described in the question it can be said that the loss is suffered by Sports Merchandise. This is because a the seller of a good or product is liable for that product until the buyer purchases the product and decides to keep it. Which in this scenario since Sports Merchandise made a mistake on the product size and Quest decided not to accept the product then the responsibility and risk of loss remained with Sports Merchandise as the owner of the product.