While Business Use Case diagrams, User Stories and support documentation can and should be sent back to the customer periodically for them to review; it is also important to have at least one, probably two more meetings with the customer where each of the Business Use Cases and User Stories is reviewed by both the requirements analysts and the customer jointly.
During this phase of the requirements gathering, each User Story or Business Use Case should be reiterated to the customer from the understanding of the requirements analyst. Any areas of confusion (no matter how minor) should be voiced by the requirements analyst to allow the customer to provide further clarification in context with the larger topic. Additionally the customer should be following along with the description closely to see if any information is being omitted. A second requirements analyst should be in attendance with this meeting to observe the customer's reactions looking for possible areas of confusion. The second requirements analyst should speak up only when they feel the customer may have something to say, but is afraid to interrupt the meeting progression. To avoid an awkward situation where one person seems to only be watching the customer, the requirements analysis team should have decided which requirements each of them will explain and trade off periodically.
After each of the Business Use Cases and/or User Stories is verified, it becomes available to begin the process of being broken down into actionable tasks for the Backlog. While these items will likely not be placed in a high priority in any iteration until the entire scope is defined, this allows the requirements gathering to be completed in a more efficient manner.