There's no formal media report on this, the stories that hit Chinese internet headlines are anecdotal and seem quite sensationalized.
The stories alledge that he argued with his Indian boss (which commonly features in all kinds of Chinese stories about Sillicon Valley tech companies), was denied request to change group, an emergency project was assigned to him, attempts to extend the dealine failed, the fear of being fired and family visas revoked drove him to that tragedy.
The story went viral in China, played on his past of being local National Exam champion from modest upbringing, and the popular notion of Chinese being coolies in SV and widely discriminated in the US.