Desperate nations do desperate things.
Japan attacked Pearl Harbor in response to the US cutting off its oil supply. Seems pretty stupid now, and it did have blowback on Japan.
China with the demonstrations and tariffs was on the ropes. Was this a desperate, modern-day Pearl Harbor attack?
I don’t know for sure but I’d say the odds are pretty good.
And whether they engineered it or not, and whether they released it on purpose or not, the DID intentionally spread it. So they are just as guilty as if they engineered it and released it on purpose.