I am absolutely horrified by these sorts of stories. How can this go on without the officers being made accountable?

The bigger problem is that everywhere with hierarchy has been infiltrated in the same way. From police, to corporations, to government. The rotten apples get in and work their way up. Then as they begin to own the higher levels, the good cops/workers leave in disgust, which unfortunately leads to few good workers and many corrupt ones (covering each others bad work).

Police must be made accountable to the public once more. We need to get back to the days of police being highly regarded peace keepers, respected by the community, preferably on foot patrol once more.
Your action of pointing out to one officer his contempt of the very rules he was enforcing is commendable and more should do it, but look at the response from the officer.... No regard at all, and an annoyance at even being spoken too. Pitiful.