The man, aged about 30, retaliated with a punch and fell to the ground.
"It wasn't a full-on bashing," the witness said. "It was just a smack in the face and he tipped over and hit the ground hard. Fitu had hit him a couple of times and the young fellow hit him back as a natural reaction."
The first punch from Mr Leau took everyone by surprise and the younger man who punched him back was "shattered" by what happened, said the witness.
Mr Leau was described as being "part of the furniture" at the Putaruru Hotel bar. "He was always dancing and stuff - dancing away to himself. He was a face you would see in the pub all the time."
Video of the scuffle was captured on the pub's CCTV cameras, and has been handed to police.
Detective Inspector Tim Anderson said yesterday afternoon they had been speaking to witnesses who were at the hotel on Saturday night and appealed for any others to contact the Putaruru police station.