While in the congested outdoor area, the victim was carrying menus in one hand and money in the other.
She tapped one of Flett's friends on the shoulder to get past him.
The defendant responded by reaching out and grabbing the woman's left breast.
''He did this by using his thumb on the top and fingers underneath and squeezed for about one second,'' a police summary said.
The victim was left ''outraged and shaken'', court documents said, and she told Flett immediately his actions were inappropriate.
When police became involved, the man tried to explain the molestation.
''I thought it was a joke at the time, she gave me verbal s..., so I did that back,'' Flett said.
Judge Turner noted the victim suffered significant repercussions as a result of the incident.
She attempted to go back to work the next day but found herself crossing her arms to protect herself, he said.
She later left the job.
Flett apologised to his victim at a restorative-justice conference, which she accepted.
He told her he was attending alcohol counselling and she was satisfied with his efforts to address his issues.
The victim did not want Flett to receive further punishment but the judge had a different take.
He imposed 100 hours community work and six months supervision.
Flett was ordered to pay the victim $1000.
Counsel Anne Stevens QC also confirmed her client had made a donation to Women's Refuge.
She objected to Flett being photographed because he had ''been through a very humiliating exercise'' but Judge Turner granted the application.