In that case, no one can make this guarantee. The author's home might be infiltrated, or the might be threatened with death in order to force the information.

Suppose this were to go to court. If there are multiple interpretations for a phrase, and one interpretation is not realizable (due to almost tautological reasons), then the courts are very unlikely to use that definition. Instead, they will likely say there were implicit qualifiers like "to within the limits of what it allowed by the law" and "unless believably threatened with the loss of life, limb, home, or similar serious physical threat" or "following information security principles appropriate for the expected threat model of an civil/economics topic".