Reproduction steps: 1. Setup generic LDAP user repository (RW), with jira-users, jira-developers, jira-administrators groups. 2. Create user for John Smith as firstname.lastname@example.org. 3. Add him to jira-administrators group. 4. Remove user email@example.com (John changed the company). 5. Create user for Jake Sunny as firstname.lastname@example.org.
Result: newly hired Jake Sunny is administrator, now.