Not the skullduggery you want to make it out to be. It appears to be simple failure to warn due to poor police procedure. The people involved in OWS have rights and those rights are being protected.
What you have failed to mention is that the judge did not find a "pattern of misconduct" for which Bloomberg, Kelly and the City did nothing, therefore, "the ruling dismissed the mayor, the police commissioner and the City of New York as defendants in the suit, saying that there was insufficient evidence that those parties were responsible for any misconduct by the police."
Judge Allows Protesters' Suit Against Police to Proceed - NYTimes.com