Thinking she wanted to discuss work, the man led her into a meal room at the premises.
The Otago Daily Times cannot reveal the nature of the allegations Falloon put to the man, or his identity; but he denied any wrongdoing.
Unsatisfied by his denials, the defendant grabbed the victim's right hand.
''While holding his hand she made two quick swipes across the top of it with a knife that she had brought to the scene,'' a summary of facts said.
She always carried the weapon with her, she later admitted.
While one of the slashes caused only superficial damage, the other exposed tendons and severed nerve endings in the area.
Falloon then produced a note of apology - as though written by the victim - and demanded he sign it.
She told him if he went to police he would find himself in trouble with Black Power members.
Crown prosecutor Marie Grills said the victim required nine stitches for his injury and might need plastic surgery in future.
She said there were elements of vigilantism and it was clear Falloon planned the attack and its aftermath.
The defendant had come to court prepared for a jail stint, counsel Rhona Daysh said.
''This incident will live to haunt her for the rest of her life,'' she told the court.
But Judge Ingram called it a ''classic case'' for home detention, after considering Falloon's background and current circumstances.
''You have spent most of your adult life caring for other people who aren't capable of caring for themselves,'' he said.
''The business you operate likewise seems to involve a whole lot of people effectively taking advantage of your generosity.''
Falloon was sentenced to 12 months' home detention - the maximum such sentence.
