All of the above..
A. Intentional Government Program-Bio war study,
The Chinese are not only capable but intentional
B. Intentional Release, a precursor/assessment attack prepping the battlespace
Again the Chinese
C. Staff Profiting/Unforeseen consequence
The Chinese want to thin the herd at home, raise prices on the world markets, and blew it with (intentional/unintentional) release on BIO weapon that was out of control from the get-go.
D. Accident/stupidity/Carelessness
YES
Now the Russians and Saudis are jumping in by crashing world oil prices to get their fair share(??)
Be prepared to buy (cautiously) on the fall...