As this video from the Real News suggests, the focus on one power-tripping cop obscured the broader story of how the police were abusing the power of preventive detention. Apparently wearing a bandana and having a lawyer's phone number written on your arm were reason enough for them to target you.
I'm sure an independent inquiry will get to the bottom of this.
UPDATE: More detail about Officer Josephs and assholes in uniform generally from the often-snarky, always-worthwhile Sabina Becker. Knowing that guys like this think of us as human garbage and don't like the thought of being held accountable really makes you think twice about taking to the streets. Just a coincidence, I'm sure.