I'd love to see a statistical analysis of whistleblower deaths on the US over the last 15 years. I'd be extremely susprised if it wasn't enormously anomalous.
This guy had plenty of money for a therapist to help with his mental health issues.
What more do you think we could we do for them?
Publicly making claims and being named as a potential witness in a court case seems a clear line.
F.ex. the resources listed on the US House's Whistleblower Ombuds page: https://whistleblower.house.gov/whistleblower-support-organi...