The only time the author mentions administrative interviews, or promises of non-investigation, is in the context of: 1.) You're a government employee, and thus

The only time the author mentions administrative interviews, or promises of non-investigation, is in the context of: 1.) You're a government employee, and thus not answering will result in your losing your employment 2.) You're working for a private employer who states that continued employment in contingent upon being interviewed 3.) You are the officer or director of a company that is regulated, or does business with the federal government, and not being interviewed could result in sanctions from the federal government. I don't see it prudent to submit to an interview even when the agents assure you that the interview is only administrative or that they are not investigating you. Other people, with advice of counsel and hopefully with counsel present, may find it appropriate in those instances to be interviewed rather than lose employment or face federal sanctions.