Case involved a very complex brawl.
The outcome from the CA was that it is for the jury to decide if the action went beyond the scope of the JCV and that a joint enterprise could occur on the spur of the moment taking into account the relevant knowledge of the defendants, e.g. a fight erupts and in that fight a few people decide to kill V.
In deciding if Defendant had withdrawn from the JCV they should ask whether he was “still in it,” e.g. where a group of people are attacking V, if Defendant was still present and encouraging them then he was clearly “still in it” (as in this case).