NRL head of football Graham Annesley has defended the match review committee over the decision to clear Matt Dufty of an alleged shoulder charge in St George Illawarra's loss to Penrith. 

The Dragons fullback appeared to use his shoulder when attempting to stop Panthers rookie Brent Naden in a try-scoring play. 

Dufty escaped a charge following the clash despite being penalised on-field by referee Grant Atkins at the time of the incident for what he described as a shoulder charge. 

The Panthers lost Viliame Kikau to the sin bin in the second half for a late tackle on Darren Nicholls, which was later deemed to be a shoulder charge attempt with the Fijian international to challenge the decision at the NRL judiciary on Tuesday night.

Annesley said the incidents couldn't be compared while he showed three similar cases – including the Billy Slater tackle in 2018 before the grand final – as examples to indicate the committee got the decision right.

"If you look at it with the exception of the Billy Slater charge we've seen a number of these tackles where they've been dealt with by a penalty with no further action," Annesley said.

"The type of tackle the game set out to prevent was the head-on collision between a player moving directly towards a player carrying the ball instead of trying to wrap the arms around to make a tackle he drops the shoulder into the attacking player.

"These are very different and although they do involve the use the shoulder they become more glancing blows side-on than the head-on collision that we were seeing when shoulder charges were legal."

Annesley said if the tackle became more common it would be reviewed at season's end but for the time being he was comfortable with how that ruling was being judged.

"We discussed this at the competition committee last year and we'll discuss it again this year because we are seeing these types of incidents," he said.

"It depends on the incident, the match review committee does still have the right to charge a player.

"They can take into consideration if there was a degree of force or had a dangerous outcome or not.

"It's not as straightforward as the traditional shoulder charge banned a few years ago. It is a last-ditch attempt to stop a player from scoring a try.

"I think it's too early to pre-empt it may change [long-term]."

In what was a quiet week for Annesley compared to previous in discussing the match official's performances.

He believed other contentious calls were correct including the Corey Oates penalty try against the Bulldogs and a knock-on call against the Knights that saw Sydney Roosters rookie Nat Butcher race away for a try untouched.