The bystander effect is a real, observed psychological effects. The tragic and unintuitive fact is that the more people are present at the scene of someone needing help the less likely any individual will be motivated to act. As for elements unique to Chinese culture, some years ago there really were scams where someone would pretend to be hurt and then sue whoever tried to help them, accusing them of causing the injuries. I don't think this type of scam is common anymore, and China recently passed a "Good Samaritan" law to prevent stuff like this, but the mainstream perception in China hasn't caught up with reality yet, sad to say.

As a Chinese person, I am extremely grateful to Stephen Ellison for saving the woman, but I also don't really blame the bystanders for not acting faster.