Agree, the tackle was dangerous! Would never try dispute that! But IMHO not worthy of the red...
Warburton's red card effectively ended the contest. That Wales got so close to winning is a tribute to them and a reflection on how s hit this French team really is.
Allain could quite easily have given a yellow card plus the penalty and both his employees and the viewing public wouldn't have questioned the decision. That he gave red changed the entire dynamic of the game and IMHO completely spoiled the occasion.
Folk are saying the rules are the rules and the occasion should have no bearing on the refs decision. I'm saying the paying public and the popularity of the sport are what enables people to make a living out of playing rugby. The world cup is a massive advertisement for the sport so when a ref shows over exuberance, acts impulsively without consulting with his touch judges, immediately red cards a player who has a reputation for playing within the rules of the sport and ruins what effectively was shaping into an amazing contest, the sport as a spectacle has become tarnished and with it its popularity.
Red carding or yellow carding the player after the dangerous tackle is not going to prevent the severe injury. That's why I consider it counter productive. Censorship needs to come but not by sending the player off the field as this changes the dynamic of the contest to the point where it now becomes potentially dangerous for the 14 playing 15.
The nature of the punishment needs to be considered:
If a yellow card is issued to the defending team in the red zone, the attacking team should be awarded a penalty try.
If a yellow card is issued any where other than the redzone the guilty party/team should concede a penalty at the prejudiced parties area of choice. So if they want to kick it over from right in front so be it. Either way the infringement results in points.
Red card results in a penalty try and a 10 minute binning of the guilty player but 14 vs 15 has to be the exception to the rule rather than the norm.
5 red cards incurred by a player equals a lifetime ban from the sport.
10 yellow cards incurred by a player equals a lifetime ban from the sport.