From hero to zero, why Cai?

Till three weeks ago, he was called a patriot, considered a national hero. Today, he is derided as an irrational and untrustworthy man, who embarrassed the Chinese the world over.

Cai Mingchao's rollercoaster fate over the last few weeks is as dramatic as it is confusing.

Why did public opinion of a man change so drastically in a matter of days? Can we not tell right from wrong, and felony from misdemeanor?