WASHINGTON (Kyodo) The U.S. Department of Agriculture has concluded that veal containing banned backbone material was shipped to Japan last month due to "inadequate familiarity" on the part of exporters and inspectors about the requirements.

But the findings and additional preventive measures in the much-awaited investigation report leave one big question: How could this have happened only a month after Japan lifted a two-year-old ban imposed on U.S. beef due to fears of mad cow disease?

The report suggests an underlying perception gap over food safety between the two nations -- especially for worried Japanese consumers -- as it does not address re-examining the overall safety inspection process, instead calling the incident a "unique" case.