In China the CPC exercises strict control over what topics are allowed to trend on social media, so what appears to be "mob justice" is actually a carefully curated event. The state media chose to report on this rather than ignore it. The Cyberspace Administration chose to allow this outrage to gain momentum while topics that do not toe the party line are squashed.

You cannot really compare the kind of social media "mob justice" people speak of in the west to how things are managed on the Chinese internet.