An elderly female neighbour overheard the comments and police were called.
Duty solicitor Jason Owers told Community Magistrate Robyn Paterson that Harris had been under stress at the time and was now being treated for depression and a "cardiac procedure".
Mr Owers said Harris and his neighbour were involved in a dispute for some time over loud noise coming from the victim's home, and during a prior exchange between them he had been called a "p****" by the victim.
Mrs Paterson said: "Mr Harris you need to sort yourself out as this was entirely inappropriate behaviour and your elderly neighbour didn't deserve to hear this either.
You need to sort it out with your neighbour so it does not happen again."
Outside court Harris said he had originally planned to defend the charge but decided "it was too much hassle".
"I'm aware I over-stepped my own moral boundary but I was under a lot of stress."
Harris said he intended selling his home and moving back to Auckland. The victim, who spoke on condition he was not named, said afterwards: "I hope this is the end of the matter."