Yeah, the course was a little spooky, with a professor like that.
I had a number of Chinese lab partners in several different schools. There was a sharp line differentiating those who arrived before Tianamen and those who finally came after: the ones before 1989 would talk politics, the ones after either pretended politics didn't exist or would be far more nationalist (with a small "n"
) than their predecessors.
One of these last had been a Red Guard in his early youth, serving in a gang whose job was to take grain from peasants who tried to keep it from the state. (The Guards would seize it for their own consumption.) Once the Gang of Four was toast politics was closed to him and he pursued a science career instead.