Raiders centre Joel Monaghan feels he let his teammates down and cost Australia victory after conceding a penalty try during the Rugby League World Cup final.

Speaking publicly for the first time after Saturday's final against New Zealand, Monaghan said yesterday he felt "shattered" because of his critical error.

He had been in strong form for Australia, scoring four tries in as many matches in the green and gold before a moment of madness in which he tackled Kiwi Lance Hohaia without the ball.

"When you give away a penalty try when you are down by two, I think there is something wrong with you if you don't feel shattered," Monaghan told The Canberra Times.

"It's something I'd love to take back. I've only seen two in my career, so to give one away in the World Cup isn't something I'm proud of.

"But it's just a natural reaction, I went to go for the ball, it bounced up and hit my hands, but I didn't know anyone was behind me."

Monaghan isn't convinced the decision to award the penalty try was the correct one.

He said he had relived the tackle time and time again since.

"I think it might have been a bit harsh. I thought I was going to get 10 [minutes] in the [sin] bin for a professional foul. I'm under the impression there had to be no doubt a try would be scored, and with Billy Slater there I'm not sure Lance would have got there.

"But I take the blame, the decision sits squarely on my shoulders."

It was a sad way for Monaghan to end his debut tournament for the Kangaroos.

The World Cup final wrapped up a monster season for Monaghan, who played 24 matches for the Raiders, was named Raiders player of the year, made his representative debut in Country Origin before being picked to play for the NSW Blues in State of Origin.

And despite the disappointing end to 2008, Monaghan said he was proud of his performance through the year.

"It obviously wasn't the best ending, I wouldn't have minded going out on a high, but I guess now's the time to sit back and look at what I have achieved this year.

"It's been a very good year I didn't think it would happen at all."

Monaghan admitted to "shedding a few tears" after the match on Saturday, and said the emotions were high after the clash.

"We obviously didn't play the best footy, but it was very emotional and a sombre atmosphere.

"For me, the way we ended with Canberra and then the World Cup it was a very similar feeling.

"And when you work so hard and spend every day together as a group for six weeks, to come out and not play our best really hurt."

But it's not all doom and gloom for Monaghan. He will attend Raiders teammate Terry Campese's wedding on Saturday, and is already excited about returning to training and catching up with his Green Machine teammates.

And there is one player he's particularly excited about meeting up with.

"I was very happy with [new Raiders signing] Bronson Harrison, I was watching him play the semi-final with Campo and we both thought he's a pretty handy player.

"I had a beer with him on Sunday, and I think he'll offer a lot to our pack."