Harry Hood, 46, and Ross Russell, 35, attacked Arthur Green at his home in South Ayrshire in November 2014.
The High Court in Glasgow heard how Hood’s parents said they had endured years of trouble at the hands of 60-year-old Mr Green and his family.
The judge criticised the local council’s handling of the dispute.
Judge Bill Dunlop QC suggested South Ayrshire Council should not have dealt with it by encouraging the alleged victims to move.
“The reaction of the council which I heard was disturbing,” he said.
“That they should make themselves homeless and move to an area away from the place they loved living in and to leave their home was frankly disappointing, wholly inadequate and on one view, cruel.
“That failure to act on the part of the council was explained to the court as due to there being no corroboration, as a lawyer I can say that’s nonsense.
“I am afraid I am driven to conclude that the council went for the easy option, persuading the good guys to move would be simple and more straightforward than evicting those causing the trouble.”
A jury had heard how Harry Hood flew into a rage when it emerged his parents’ window had been smashed.
Hood and his violent friend, Russell, later went to Mr Green’s home where he was punched, kicked and stamped to death.
The men fled the scene with Hood heard saying: “If I murdered him, I will happily do time for it.”
‘Got away with murder’
Mr Green’s young grandson discovered his body the next day.
The pair boasted they had “got away with murder” after police initially believed Mr Green had fallen.
After a new investigation, Hood, from Ayr, and Russell, from Maidens, were arrested.
Both Hood and Russell gave evidence during the trial and effectively blamed each other.
Dale Russell, from Girvan, Ayrshire, had also been charged with murder before prosecutors dropped the allegation during the trial.
He instead pled guilty to attempting to defeat the ends of justice by setting fire to his brother’s trainers.
He was ordered to carry out 300 hours of unpaid work.