THEY'RE human, not super heroes, so expect and accept that they will make mistakes.

That's the view of University of the Sunshine Coast senior psychology lecturer Dr Geoff Lovell after the weekend's infamous seventh-tackle try by Cronulla in the knockout National Rugby League semi-final against North Queensland.

But he also says referees' decisions can be influenced by the environment in which they're made. In other words 50-50 calls more often end up being to the benefit of the home side.

That's a view all of North Queensland would share after the Cowboys' heartbreaking two-point loss to the Sharks in Sydney.

Dr Lovell, who conducted research into the stresses faced by English football referees, said the job was incredibly demanding and stressful.

"It should be no surprise that mistakes happen,'' he said. "Players also make mistakes.''

But he said the difference was that players were part of a supportive team environment while referees could feel very much alone. He has suggested that referees may get a performance boost by using sports psychologists.

Dr Lovell said the NRL needed to ensure that any inequalities between the investment in players and the investment in referees was addressed.

The game did not exist without the referee.

He said yesterday that referees needed to be supported individually to help them cope with the stresses of the job.

"Referees are in a no-win situation,'' Dr Lovell said.

"When they do a good job no-one mentions it. But there is such a big magnifying glass on everything they do.''

He said referees needed to look at a number of things while literally on the run and were required to make decisions quickly.

It was revealed yesterday that Cowboys' coach Neil Henry did not tell his players about the miss

ed tackle count until after the game.

This was despite using as motivation all year the missed knock-on by Manly's Kieran Foran that cruelled the Cowboys' 2012 finals campaign.

Meanwhile, a Forest Glen woman is the brains behind a petition calling for the North Queensland Cowboys to be reinstated into the NRL finals.

Jacinta Vock's online petition has gathered almost 30,000 signatures and about five names are being added every second.

"I think I probably expected at best a couple of hundred or a thousand signatures and now we're at 30,000, so it's rapidly growing momentum," Miss Vock said.