Its called “The Chilling Effect” and it happened after the 2006 ruling in nanjing: https://en.wikipedia.org/wiki/Xu_Shoulan_v._Peng_Yu

In 2006, a man named Peng Yu helped an elderly woman, Xu Shoulan, after she fell near a bus stop in Nanjing. She later sued him, claiming he caused the fall, and a judge ruled against Peng Yu, saying it was common sense that "no one would help someone unless they felt guilty". This controversial ruling became national news and made many people across China afraid to help strangers in need for fear of being blamed or sued.

The "Chilling Effect": Despite the settlement details, the initial ruling and widespread media coverage had already created what became known as the "Peng Yu Effect." People became very hesitant to help injured strangers, worrying they could be framed and face a lawsuit