That's not the case. If you really watched what happened, it IS really the lack of morality.
The girl has been run over by a van/truck (can't remember) and then the driver has actually realized that. But instead of stopping and bringing her to the hospital, he attempted to run away and thus, ran over her a second time. The tricycle that passed just looked at her and went around her. Many people passed without caring about her and just looked. Not even a single person called any help or ambulance. The most alarming part is, after very long, another car came by, and instead of moving her away, it went over her, crushing her another time. You can call it crowd mentality if you simply avoid her, but to run her over another time is really just murder...
@wakarimashita: you're very right about that. Especially in guang dong province.
Oh and the law in china actually make things more cruel. The price you have to pay in an accident for killing a person is actually lesser than that if you just paralyze him. That's why if you hit the person, make sure you kill him in one hit. Else, you have to pay him for life.