A common complaint amongst FFL's is that they'll get audited one year, and make changes due to the findings of the ATF auditor.
A few years later they'll get audited again, with a different ATF auditor this go 'round. That auditor will look at what they've done, per the advice of the previous ATF auditor, tell them that it is wrong, and gig them for it.
Every. Damn. Time.