I think local laws also play some part in this. There have been cases where people who help the victims have been accused of having harmed the victims. If not that, they're hassled by Police and other investigators during the course of the investigation.
This is the reason why Good Samaritan law is being brought into effect across the world.
More culture than law - my personal experience is that sub cultures within rigid legal systems that do not make it a good idea to lend aid (China for example) will do so regardless because of their subculture value system.
This is the reason why Good Samaritan law is being brought into effect across the world.
https://en.wikipedia.org/wiki/Good_Samaritan_law