It's a bit strange that the burden of proof is on people contesting allegations about an anonymous person. As far as I can tell the original claim has no proof whatsoever.
That said, after digging into this a bit more it seems that the most credible proof he didn't commit suicide is that the U.S. State Department has no record of it. They allegedly killed themselves in June but according to government records no US citizen died of suicide in Japan in June.
https://travel.state.gov/content/travel/en/international-tra...
That said, after digging into this a bit more it seems that the most credible proof he didn't commit suicide is that the U.S. State Department has no record of it. They allegedly killed themselves in June but according to government records no US citizen died of suicide in Japan in June. https://travel.state.gov/content/travel/en/international-tra...