There's nothing like statists who fight among themselves in public, point fingers at each other, and call the other a (bigger) fascist. No doubt Blair's head will roll for this, but he is only a sacrificial lamb. Another far worse one will take his place.
I feel that one of the problems with the G20 was bringing in police forces from all over the country. When that is done it turns into a competition to see who is the best cop (badest) on the block and the attitude goes from preserving law and order to "watch how real cops handle this". With a national spotlight shining on every skirmish the common sense factor can evaporate quickly.