Sorry fatprop, but I have to call you on this one. What you said is a load of crap, and completely ignorant of the rules and spirit of rugby.
Robinson had an otherwise legal cleanout but after the whistle. At worst a penalty, at best he could claim he didn't hear the whistle as Kepu was still playing on anyway, forming a ruck over a player.
Kepu responds with a few uppercuts and some hair pulling, and you think both players deserve the bin? Mate, a late cleanout is just a late cleanout. Upper cuts and hair pulling is a straight out yellow card, heading towards red territory.
Refs need to take control early to cut out the niggle and cheap shots. When a player retalliates with a punch, that player goes to the bin. If the instigator's crime is not worthy of the bin, the instigator does not. In this case, it's a legal cleanout on a guy playing on after the whistle anyway. It's not rocket surgery.
You can get complaining about it being a late cheap shot all you want, but it doesn't change the fact that Kepu's trangression is a straight yellow, and Robinson's will never be a yellow.