Final answer:
A customer service manager handling an irate customer is performing the role of a disturbance handler, intended to address urgent issues and conflicts.
Step-by-step explanation:
When a customer service manager works to defuse a situation with an irate customer, he or she is taking on the role of a disturbance handler. This managerial role involves responding to pressures and problems so serious that they demand immediate attention and action.
The manager must act quickly to defuse the situation, ensuring that it does not escalate and that the customer's concerns are addressed in a satisfactory manner. It is different from the other options because it specifically involves dealing with unexpected issues and conflicts, whereas roles like liaison, negotiator, resource allocator, and leader have other primary focuses.