Dr Yang criticized the W.H.O. trials as not being conducted near FDA protocol and not thus, being necessarily meaningful....
However, think about this....
If they results showed very good efficacy, and very good results as to decreasing morbidity, in that case the lack of FDA trial protocal would be more significant, the results would be less certain.
But since the results showed little or no benefits, in this case, the lack of FDA protocal is not as significant, and certainty is higher.