[thinkingemote]

It's a different thing really. The old theory is not bystander doesn't intervene because it's dangerous but that they thought otter people would help.

In the UK when it's dangerous the police protect themselves as a matter of priority often retreating. This led to one situation of the knife terrorist attack on London bridge where the public did intervene and risk their own lives when the police stayed back. However it's not the case all the time with groups of people and the bystander effect and that example actually disproves the bystander effect too!