When there is a real or perceived threat to the safety of the blood supply, withdrawals occur without reference to cost or potential short-term shortages. A major withdrawal of blood products in Ontario in 2005 involved over 3500 blood product components. The reason for this withdrawal was clerical in nature associated with records of donation which are completed at the time each donor gives blood. The risk to the blood supply was likely minimal or nonexistent. Individuals in the appropriate organizations joined forces to deal with the matter. But it brought to light many of the challenges faced by both hospitals and the blood suppliers around dealing with error and emphasized gaps in the system related to timeliness; communication; risk perception; and recipient notification. It provides an example of what we call organizational 'threat' or, more positively, a learning opportunity. We suggest that this approach to identifying error as a potential for hazard and risk is useful in that it focuses attention on possible differences in organizational responses and public notification.