Yeah, his family said "He was suffering from PTSD and anxiety attacks as a result of being subjected to the hostile work environment at Boeing which we believe led to his death". As much as a conspiracy for fear of being next could come into it I'd have to believe it'd be more than a lone and anonymous friend of the family that would speak out if confided with this info.
Between that and the 30 some whistleblowers in the last 5 years that two died close to one another isn't all that damning.
https://www.cbsnews.com/news/john-barnett-boeing-whistleblow...