On July 29, Maoyi Sun approached a loud customer and asked him to keep the noise down but he reacted angrily.
"The complainant grabbed him by the throat," the judge said.
Feng and Peng Sun, concerned about their father who had health problems, jumped in and dragged the man out of the restaurant.
"It's understandable they leapt to their father's defence," Judge Sharp said.
As the fracas spilled outside, the group fell to the floor where the victim smacked his chin on a pot plant.
The 4cm wound required stitches but the judge was unsympathetic.
"During the whole fight it appears that the level of intoxication of the complainant meant he was less the actual victim than the aggressor. Put it this way: he was giving as good as he got," she said.
"It was unfortunate he was injured but I don't accept it was those three defendants who were responsible for the injury."
A passing police officer was able to break up the fight but further units had to be called in to restrain the rowdy patron.
The court heard the Sun family recently sold the business.