I think you need to reverse your cause and effect. The credit rating agencies and sell side brokers both decided that after QIN had withheld the information regarding Galderma after the Shanghai Richer link debacle, that the lack of transparency was too much. That's what caused the sell off and the downgrades - they're two sides of the same coin.
QIN Price at posting:
29.5¢ Sentiment: Sell Disclosure: Not Held