Brit female cop gets jumped in a parking garage,

and doesn't understand why nobody helped her, just yelled things and took video.

It's because everyone there knows that if they do help you, they stand a fair chance of going to jail because modern Britain, including the cops, hate people defending themselves.   And if your attacker was, let's say a culture-enriching migrant type, they KNOW they'd probably wind up in jail if they jumped on them to save you.

One of the terms is 'reaping what you sow'.