He also led with "my fellow investors", if he owns stocks in the company and released material non-public information to select shareholders I don't see how that's not an actionable offense.
The letter is calling for ousting the owners of the company which doesn't even make sense. If he was a whistle blower it would just go to the SEC and become public.
I tend to think he is that dumb. a letter like that would only crash the stock till sorted out. If he had thought it thru he would have realized he was only hurting shareholders. Never hold more than you are comfortable losing. keeps one from panicking in times like this.