Hari hari is Japanese. Chinese people don't consider suicide an honorable way out anymore (have they ever?) . Honorable suicides are more of a Japanese thing anyways.
This guy probably committed suicide because he knew his job would be finished and he may end up in prison....hey, maybe he was depressed too, and/or his wife left him. People kill themselves under pressure all the time.
Oh, and I really doubt he would have been executed. No one (as far as we know) have died. And given that this scandal has not caused nearly the same outrage as the drug one in China, I doubt he would have done more than serve a few years in jail. Although I guess Chinese jails aren't pleasant. Still, he probably had other issues to have killed himself.