"There was smashing and screaming," he told the High Court in Whanganui yesterday.
He saw Mr Rippon leave the house and approach the group with a shovel in hand.
He then heard what he described as a pole striking Mr Rippon.
"I looked back and he was on the ground.
"[I was] pretty scared and I ran home," he said.
Tyrone Peter Madams, Matthew Thomas Madams, Kevin Roy Madams, and two youths are charged with the murder of Mr Rippon, 57, and with participating in a criminal organisation.
They have denied the charges.
In June, Tyrone William Madams pleaded guilty to Mr Rippon's murder and was sentenced to life imprisonment.