Customers can not pass or cancel their claim on an item on their own. They need to notify their consultant to cancel their claim. Customers can do this by commenting on the claimed item, tagging the consultant in the Facebook group the sale took place in, or responding the the e-mailed invoice.
The purpose of this is to reduce abuse of the claim system and promote fairness in your sales and Parties. It is to prevent a customer from going into a highly competitive sale, claiming many items to "save" them, leaving them unavailable for other customers to claim, then passing after they have come to a firm decision what to buy.
For a consultant to cancel a sale of an item, click this link for instructions: https://shoptheroe.freshdesk.com/support/solutions/articles/16000085985-how-to-cancel-a-sale