Early in my consulting career, I was sent to a client organization with the goal of interviewing the only person in the organization who knew how the accounts receivable system worked, and developing documentation for that system (nonexistent at the time). The interviewee was on time, polite, and told me absolutely nothing of value about the accounts receivable system, despite my best efforts over several interview sessions. Eventually, my manager called me off this project, and our attempt to document this system was abandoned.

Why do you suppose the interviewee was so uncooperative? Can you think of any ways to avoid this failed outcome?