Sharks coach Shane Flanagan and Manly coach Trent Barrett were fined $30,000 and $20,000 respectively after the pair were critical of the referees following their losses to the Cowboys and Penrith.

It is a trend that prompted NRL boss Todd Greenberg to tell everyone in the game to “grow up” and respect the adjudicators and how difficult their jobs were.

Bellamy said major criticism from coaches of late could filter down to the lower grades and even juniors with a culture set by the people at the highest level.

"I just thought Todd handled that really well," Bellamy told AAP.

"When you're heavily involved in the game ... you know the grassroots - the kids and their coaches - they're all watching.

"Sometimes we forget that we should be setting an example for our game.

"What Todd said when he mentioned about the grassroots ...watching that (behaviour) then mimicking that - that's not on.

"That made me sit up and take a bit of notice.

"Whether you're a player, coach or administrator at NRL level we've all got a responsibility to the game.

"Sometimes we can forget that I suppose.

"It was a good reminder for all of us I think."

However Bellamy sympathised with fired-up coaches who front the media immediately following games when dubious decisions had swayed a result.

"I think it's hard when something happens in the game and you've lost then you've got to talk to your players then go to a press conference," he said.

"When there's a couple of controversial decisions what's the first question you're going to get?

"It would be great if you could do it the next morning but I know that's not a viable proposition.

"To go into a press conference and you're boiling up over something whether it be referees or whatever - it's hard for that not to come out."