As a leader myself that leader should not have even contacted you about it, that is a breach of privacy. No one is allowed under any circumstances to tell a third party that a check was returned, that is private business and now your friend has every right to complain to the BSA head offices and that leader can lose their position over this. Stay out of it completely concerning collecting anything. You will have to decide if you should tell your friend that their privacy was violated. It doesn't matter if the person routinely bounces checks all over town, that is their business, it's private, and it is a violation and in most states illegal for the matter to be discussed with a third party.