Rush told the Northland Age this week he had little choice but to break up the post-match fight.
He had held the collar of an Eastern/Waipapakauri player, who had been prevented from fighting by parents, to stop the player rejoining the fray.
"I just held him until it [the fight] was all over so he couldn't get back in there. I am not going to stand by and watch someone pummel someone else. Are we expected to stand by and see kids get beaten up?"
The fighting and conduct of players and adults associated with the team is under scrutiny from the Northland Rugby Union as well.
Earlier this week, Northland Rugby Union operations manager Kyal Collins told the Northern Advocate there had been serious etiquette issues surrounding the match and management of both sides would be asked to address them.