The federal law known as HIPAA does not create a private right of action for damages. It is enforced by a federal agency and may result in a fine or injunction against the violator. Furthermore, a worker's compensation case worker is not a health care worker. HIPAA generally only applies to health providers or health facilities but there are exceptions. Check with an Ohio attorney for a tort known as either invasion of privacy or improper disclosure of private information. You will have significant immunity issues going against the woker's compensation worker as they are probably a government employee. Depending on your state's law, you may have a claim against both the government worker and your former co-worker.
There are numerous issues that may arise in the denial of advancement. The employer/employee relationship is greatly influenced by state law. You need to consult with an attorney about those issues.