The NRL sin-bin was heavily used during Canberra's upset 24-12 NRL win against St George Illawarra on Saturday night but both team's coaches remain tight-lipped about its use.

Three players found themselves on the sidelines and another was lucky to avoid the same treatment at Canberra Stadium.

The high-intensity clash first bubbled over at the 18-minute mark, when a tackle involving Canberra five-eighth Terry Campese and St George second-rower Dean Young escalated into a brawl that saw Young sin-binned for 10 minutes.

Already on thin ice, Campese soon found himself sent off for 10 minutes after backchatting the referee.

The trend continued in the second half, with Dragons forward Jeremy Smith copping a sin-binning for a late shot on Raiders centre Jarrod Croker.

Canberra lock Josh Miller was lucky to stay on the field after match officials missed him trading punches with St George prop Justin Poore, who ended up being penalised for the altercation.

Dragons coach Wayne Bennett wouldn't be drawn on the enthusiastic use of the sin-bin.

"I don't really want to comment on that. It will take me nowhere," he said.

Captain Ben Hornby said Miller's escape was disappointing but Raiders coach David Furner came to the 26-year-old's defence.

"I did praise my side. We've got a couple of young kids there and I thought there was probably a couple of cheap shots on them," he said.

"What I did like was our ability to rally behind them and I did give them praise because when that happens you've obviously got to stand up for your teammates.

"Joshy Miller didn't go out to start anything or to get into a fight, none of the players did.

"But they played with a lot of aggression there and sometimes (a fight) happens."

Campese said he thought the referees may have cracked down too hard on players.

"I'm not sure if there was any need for any of (the sin-bins) to be honest, but that's just how the refs try and control the game," he said.

"It was great to watch anyway."