France's Romain Taofifenua avoided a red card for a high tackle on Thursday, raising more questions about inconsistent decisions from officials at the Rugby World Cup.

But his yellow card was not upgraded to a red by the bunker review system.

Sekou Macalou's involvement in the tackle proved to be a mitigation.

Taofifenua, 33, is the third player this tournament to be sent to the bin before a review by the new bunker system has then considered whether to hand out any further punishment.

England's Tom Curry was the first and his head-to-head contact in a tackle with Argentina's Juan Cruz Mallia was deemed enough for it to be upgraded to a red card.

It means Curry will miss England's next two matches in Pool D against Japan and Chile.

Since Curry's sending off, Chile captain Martin Sigren received only a yellow against Japan and South Africa centre Jesse Kriel remained on the field without even a review against Scotland for similar-looking offences.

There were also concerns over Wales fly-half Dan Biggar's upright hit which appeared to make contact with the head of Fiji centre Semi Radradra.

'Unbelievable that he is still on the field'

Here is some of the reaction to Taofifenua's tackle on social media:

Jared Wright: I don't think they will need 8 minutes to decide this one. Always dangerous and reckless. Easy red card. Silly from Romain Taofifenua.

Joe Naughton: Ah come on, how is that not a red card for Romain Taofifenua, World Cup haven't got a fog sometimes. How the mitigation was sufficient is laughable.

Regine Edimo: I give it up to rugby! I love Romain Taofifenua, but it should be a red card! What an embarrassment from refs and TMOs

Ross Barnett: Think this will be upgraded, don't see any mitigation as there's no wrap from Romain Taofifenua

Peter Brook: That Romain Taofifenua mistackle is the most nailed on red card I've ever seen. Unbelievable that he is still on the field.

PG: Romain Taofifenua can consider himself very fortunate to still be on the field. Wrong call by the bunker system.

What is the bunker review system?

The bunker review system was introduced at senior level during rugby's Summer Nations Series, after World Rugby had used it at the World Rugby Under-20 Championship in July.

If, after two video replays, the on-field referee is unable to decide if an incident deserves a red card, they have the option to show a yellow card.

That then gives a television match official (TMO) the chance to have a detailed look at the incident in more detail, with all angles available.

The "foul play review officer" (FPRO), situated within the TMO bunker, will have up to eight minutes to review the incident and communicate the decision to the in-play officiating team.

The yellow card can then be upgraded to a red card with the player not returning to the field of play. This helps to avoid players being wrongly shown a red card, as England's Freddie Steward was in the Six Nations in March.