You should hear that candidate is well-mannered, well-tempered, and reliable when dealing with customers.
You should hear that applicant is cautious while interacting with customers and co-workers to avoid future problems, that they think about the long-term, and that they want to maintain positive, personal, working relationships.
Answer should show that applicant is well-tempered, able to control and safeguard professional interests in agitated situations.
Applicant should show that they do not let personal ego come in the way of professional behavior. Notice if they can take criticism well and if they see the value of positive criticism.
Answer should show that he/she can balance confidentiality and communications with co-workers, can keep necessary information confidential, and does not feel bad about keeping confidential information from co-workers.