To play a bit of a devil's advocate... I don't think anyone knew it was coming, including Ryker. How I see the scene play, most of it was in the heat of the moment. If you remember they were there looking for Charles, for something unrelated to the charity event and the argument with the MC started all that followed. From how is presented it wasn't a premeditated action.(and don't anyone give any 'he didn't actually hit anyone' BS, he knew it was coming and didn't warn anyone, that makes him complicit in everything the others did).