Probability of death by suicide by a 26 year old

It does seem pretty suspicious.

I'm like 98% confident this was not foul-play, partly because I doubt whatever evidence he had would be that important to the court case and obviously his death is going to draw far more attention to his view.

However, 98% is still quite worrying and I wish I could be >99% confident. I will be interested to see if there is further evidence. Given OpenAI's very shady behavior with the secret non-disparagement agreements that came out a few months, it doesn't seem completely impossible they might do this (but still very very unlikely imo).

The probability of a 26 year old dying of suicide in any given month (within the month of being named the key witness in the OpenAI copyright case, right before deposition) is roughly 1 in 100,000

This prior is a useful starting point, but you've definitely got to account for the stress of leaving OpenAI and going through a lawsuit.

(I downvoted this post for combative tone.)

Whist-blowers commit suicide rather often. First, they are already stressed by the situation. Second, they may want to attract attention to their problem if they feel being ignored or even punish the accused organization.  

Among 'hidden actions OpenAI could have taken that could (help) explain his death', I'd put harassment well above murder.

Of course, the LessWrong community will shrug it off as a mere coincidence because computing the implications is just beyond the comfort level of everyone on this forum.

Please don't do this.