David Gorman, of 2 River Cottage, Main St, Carrigaline, Co Cork, was returning home after 9pm on February 22 when he believed that a man was urinating in the alleyway.
Inspector Finbarr O’Sullivan said the man complained to gardaí that he was merely zipping up his jacket when he was approached by the accused who accused him of urinating in the alleyway beside his house.
He said the accused then went into his house and returned with a knife and shouted at him in a threatening manner.
Judge Olann Kelleher imposed a €350 fine on the accused at Cork District Court on a charge of producing a knife on the occasion.
Michael Quinlan, defence solicitor, said there had been an ongoing problem in the area with people basically using the lane as a toilet. He said Gorman was returning from a chipper and saw this man and he believed he had been urinating there and he reprimanded him.
Words were exchanged and Gorman cracked and went home to get the knife — and since then totally regretted taking the law into his own hands, Mr Quinlan said.