The South African referee ran straight from the field after blowing the final whistle amid jeers from Scotland fans. Former internationals labelled Joubert “a disgrace”.

Rugby’s watchdog rarely makes such damning verdicts public. While the review committee called out the 37-year-old Joubert, it said he remains an “important” member of the referee team.

He was not named to officiate the semi-finals this weekend however.

The Scottish Rugby Union said it would make no comment on the decision, indicating the storm was now over and the result should be left to stand.

With Scotland leading 34-32 in Sunday’s quarter-final, Joubert penalised Scotland’s Jon Welsh for offside for playing the ball following a knock-on by a team-mate.

After reviewing television images, the committee said it was “clear” that after the knock-on, Australia’s Nick Phipps touched the ball and that a player can be put onside by an opponent who intentionally plays the ball.

“The appropriate decision, therefore, should have been a scrum to Australia for the original knock-on.”

The six-member committee – headed by former Scotland flanker John Jeffrey – stressed though that as no foul play had been involved, Joubert could not have referred the incident to the third match official and a television replay.

World Rugby referees chief Joel Jutge said: “Despite this experience, Craig has been and remains a world-class referee and an important member of our team.”

Joubert faced as much criticism for running from the field as he did for the decision.

“Maybe he was keen to get to the bathroom, who knows?” World Rugby chief executive Brett Gosper told BBC radio.

“I’m sure as a referee he sensed a bit of hostility,” Gosper added.

“When you have a hostile 82,000 people, for whatever reason, who knows how that affects behaviour.”

“Craig Joubert is a superb referee and has been for a long time and he’s a good man. There will be reasons for whatever Craig did.”