NRL head of football Graham Annesley says a controversial penalty given against Wests Tigers winger David Nofoaluma was technically correct but in an ideal world play should have continued.

In the winner-takes-all clash at Leichhardt Oval on Sunday, Nofoaluma was penalised in front of his own posts after being judged to have played-the-ball before a tackle had been completed following an attempted strip by the Sharks.

The Sharks took the two points on offer to take a 6-4 lead to the break before running away with it in the second half and earning a finals berth at Wests Tigers' expense.

"Obviously it's a big swing in momentum when the team in possession is penalised, particularly so close to their goal line," Annesley said in his weekly football briefing on Monday.

"The interesting part of the ruling is technically the referee was right, players can't determine when the tackle is completed and when they play the ball.

"If they do decide to play the ball before the tackle is complete they can be guilty of a voluntary tackle, that's technically under the rules.

"However in this case, given the policy direction I've been giving to match officials to try and stay out of the game and keep the game flowing as much as possible, this is an example where there's no real benefit to stopping the game in this instance."

Annesley also said a scrappy and messy try awarded by the NRL Bunker to Manly's Manase Fainu should not have been awarded.

With Manly attacking the Eels line, two Parramatta players pulled the ball free with Tepai Moeroa then knocking on and regathering. He then lost the ball, which was kicked ahead and grounded by Fainu.

While Manly would have retained possession, play should have been stopped as soon as the Eels regathered possession, according to Annesley.

There was another try incorrectly awarded by the NRL Bunker to Canterbury winger Nick Meaney with an obstruction missed in the lead-up of their 30-16 win over Brisbane.

While lead runner Corey Harawira-Naera did not impede the Brisbane defence on the play, fullback Will Hopoate caught the ball on the inside shoulder of the lead runner before passing to Meaney, which has consistently been ruled an obstruction this year, Annesley said.

"What was missed in this instance was where the receiver received the ball," he said.

"We've talked all year about the significance of the ball receiver not receiving the ball on the inside shoulder of the lead runner. The moment that happens that becomes an automatic penalty."

While the benefit of the doubt goes to the attacking team if the officials can't tell if the ball was caught on the inside, there was enough evidence in this case to rule no try, Annesley said.

Annesley also issued a general warning to all clubs about trainers stopping play over injury concerns before they had checked whether a player was seriously injured, which he said makes a "mockery" of the intent of the rules.

"Whilst we want to make sure the players get the best possible treatment as quickly as possible, unfortunately, we have seen some incidents in recent weeks where trainers are stopping the game without going through the correct process," Annesley said.

This is an example where there's no real benefit to stopping the game

Graham Annesley on the David Nofoaluma penalty

"We've seen some instances where trainers are going to the referee to stop the game before they examine the player.

"The rules are very clear that the trainer has the right to call for the referee to stop the play if he believes a player has suffered a serious injury after he examines him. If you haven't examined him it's very difficult to take that view.

"We don't want to see teams disadvantaged through any breaches of the rules."

Annesley said any clubs in doubt over the correct process can contact the NRL for clarification but warned breach notices and monetary fines could follow if the correct process is not followed through the finals series.