Venky,
In this whole scenario, I wonder how your company can purport to certify traceability (e.g. lot numbers, expiration dates, etc) when you don't even know for sure how (or if) the original error occurred.
If it were my company, I would be disinclined to certify traceability for these overages. An unscrupulous customer could be using this method to bypass legal restrictions.
Best Regards,
DB49