What seems to be missing here is some sort of controlled method for correcting errors in records. There have been discussions here in the past where it was suggested that records should never be corrected or altered, but that makes no sense. Where there are errors or misstatements in important records, they should be corrected. What's needed is a written procedure that describes acceptable methods, along with roles and responsibilities. You always have to be on the lookout for instances where records have been falsified, of course, but it's really important to codify acceptable methods for making corrections and provide swift discipline when the rules are broken.