Legal Question in Personal Injury in California

Based on these very limited facts, I think your claim would be barred by the common-interest privilege. That's a hard privilege to explain, but it basically says that two or more people who have the same legal interest in information about another person are allowed to share that information without risk of a defamation judgment. Because the people who see your medical charts all have an interest in promoting your health (and probably all work for Kaiser), statements in your chart would probably qualify.

I can imagine many reasons why the privilege might not apply in your case. With so little information, I can't say whether any of them applies or not. You may want to consult with a lawyer for a more thorough analysis.