How do you stop made up values for fields that are not there?
Extracting fields from 200–400 page reports, a user finds the model invents numbers for fields the report does not contain instead of saying "not found", and extra passes are too expensive. The fix that works is requiring a quoted source snippet with every value and checking mechanically in code that the quote actually appears in the document. Making "not found" an explicit valid answer removes the ambiguity of a blank field.