HIPAA is a law that requires covered entities to keep confidential protected health information (PHI) and not disclose it to others except as permitted by the HIPAA law and the HHS regulations that implement it. One of those exceptions is when the patient authorizes the disclosure. The second hospital didn't get you to sign the authorization to get the PHI from the first hospital. But why is that a problem in getting the insurance company to pay? If the insurance company needs information from either hospital to process the claim, then all you need to do is sign an authorization allowing for them to obtain that PHI from them. So what is really causing the hold-up here? The authorization problem is easily fixed, so I'm not seeing where that is an obstacle unless you've be unwilling to sign off on it, in which case that's on you.
Where is the HIPAA violation? In other words, which hospital disclosed your PHI to someone else without meeting one of the exceptions in the HIPAA statute and regulations and how has that disclosure resulted in problems in processsing your claim? There's a disconnect here between a HIPAA violation and the insurance claim, and you'll need to explain what the violation was and what connection it has to the insurance company holding up payment for much useful comment.
What I can tell you is that you may not sue the hospital for a HIPAA violation. HIPAA only allows the U.S. Department of Health and Human Services (HHS) to enforce the law; it does not authorize lawsuits for damages by persons whose PHI was improperly disclosed. It's possible that improper disclosure might give you a claim under state law, if you end up suffering any damages from it.
