Yes, bjohn, the mind of the CPS works in mysterious ways. My guess is that they were interested in the words 'their conduct taken together' [s3(1) of the Public Order Act 1986]. They felt they had other, more general, evidence of affray and that the action caught on tape, which got all the publicity, was only part of the picture, which was that he was part of a common activity or enterprise amounting to affray.They might then squeak home even if he got a defence to assault in the particular instance up and running. They must have been disappointed when the others pleaded guilty because that may well have left a lot of evidence out (including any which the defendants might give in their own defence, which is rarely helpful to any of them), but, in any case, focussed the jury's mind on the one bit. !