This is ridiculous. The linesman clearly had a good view but lacked the confidence or the steel to give a red card, as by 'law' a tip tackle is red. Warburton gets a Red, Ioane gets 5 weeks and there have been countless others not given or yellow carded. Until there is some consistency in the refereeing across the globe then this will always be a debate. Referees are more than willing to leave it to the Citing Officer or too meek to act.