The boss of World Rugby has rejected Australia coach Joe Schmidt's claim that the decision at the end of the second Test against the British and Irish Lions contravened the sport's player welfare drive.

The officials decided not to overturn Hugo Keenan's series-winning try after reviewing a clearout in the build-up from flanker Jac Morgan as the Lions snatched a late victory in a compelling contest at the MCG.

Wallabies coach Schmidt said it was a call that "didn't live up to" World Rugby's focus on player welfare.

"I don't agree with that," World Rugby chief executive Alan Gilpin told the Rugby Union Weekly podcast in Sydney.

"We're trying to find that really tricky but massively important balance between a sport that is a brilliant physical contest and as safe as it can be for the players. It's a very tough balance."

The incident occurred in the last passage of play in a pulsating contest in front of 90,000 fans at Melbourne's fabled MCG.

As the Lions attacked near the Australia line, Wallaby flanker Carlo Tizzano tried to get over the ball at a ruck.

With Tizzano bent over - and his head well below his waist - in the classic 'jackaling', external position, Morgan drove into him to prevent him from stealing possession from the Lions.

Morgan appeared to make contact with the neck and shoulder area of Tizzano, who lurched backwards out of the breakdown, but with both players so low referee Andrea Piardi decided Morgan had made a legitimate attempt to ruck him off the ball.

After the ball was then worked out to the left for Keenan to score, the referee discussed the collision at the ruck with the television match official and decided to stick with his initial decision that it was not a penalty, and to award the try.

After the match, Schmidt cited rugby's law 9.20, external which says a player must bind on to another player as they enter a ruck or maul and must not make contact with an opponent above the line of the shoulders.

World Rugby chief Gilpin added: "I understand emotions are running high and I understand Joe's looking at specific laws and playing that into the sort of officiating and welfare debate.

"But Joe knows well, and so do all the international coaches, that we are investing heavily [in player welfare], whether it's instrumented mouthguards across the professional game, whether it's all the investment we make in the science and research.

"One of the great wonders of rugby is the complexity of our laws and the interpretation of that. We know that creates controversy and sometimes frustration but it also gets everyone talking about rugby, and talking positively about rugby and what an amazing game it was."

Gilpin would not be drawn about whether figures at Rugby Australia had lodged a formal complaint, but said the referees' body had been going through their customary review of the game over the past few days and that the officials "stand by their decision".

"We've got to back our referees and our match officials. And we do. They're making 800-plus decisions under incredible pressure in front of a global audience in a single game," he added.

"And they don't get every decision right. But as long as they've gone through the right process and as long as they've got a decision that they can stand behind, then we'll support them."

Meanwhile, Australia fly-half Tom Lynagh has asked whether any review findings into the decision should be made available to the public.

"I think it's a grey area," Lynagh said on Tuesday. "I think it would be good for the public to know the final result.

"But unfortunately it doesn't change the result of the fixture, the decision is final."

Former Wallabies captain Michael Hooper has been among those vocal in the Australian media, saying it should have been a penalty against Morgan and the Lions for a dangerous ruck entry.

But he adds that now is the time for the hosts to move on and focus on the third and final Test in Sydney this weekend.

"It's the game, right," he told Rugby Union Weekly. "But these things happen and if being a player teaches you anything, it's that you have to move on.

"I hope the Wallabies have had a couple of days just to grieve, get it over with, and to get mentally prepared to bring it this week."