I had resisted doing anything with the shared passwords prior to this because the process to unshare an account is to delete it from the organization and make a new entry on your personal vault.
Ultimately the blame is on me but the process for unsharing is broken. I guess the moral is to just be careful about sharing accounts in a BW org if you ever expect you might have to undo all of them. It was about 15 accounts in all because we had also shared everything related to financial institutions and health care. I did take the time to change each of them as well since there was no way of knowing what may have been copied.