On 26 October 2012, the Dutch Supreme Court agreed with a whistle-blower of the Theodoor Gillissen Bank ("TGB") about when a person may communicate internal issues to a customer. 

The case focused on a customer of TGB which may not have been treated properly by TGB. The responsible relationship manager informed the client about this. In short, the Supreme Court ruled that under the circumstances the employee had not acted in violation of the rules and code of conduct of TGB by providing his client with confidential information. According to the Court, there was sufficient justification for piercing the contractual duty of confidentiality. In addition, there would have been no sense in the employee first internally airing his objections since under the specific circumstances internally submitting a complaint to a TGB officer or manager would not be expected to have had any effect. 

This decision partially reverses the earlier decision of the Amsterdam Court of Appeal. The Court of Appeal had inter alia ruled that the employee should have first discussed his objections internally and have indicated that he would refuse to cooperate in actions that he found unacceptable. Furthermore, the Court of Appeal had found that he had not served any important public interest by his being a whistle-blower.