One of the killers, Steven Archibald, was still complaining about paint damage to his jacket when police detained him after the fatal attack on former soldier John Auld.
Archibald and his accomplice Michael Sutherland ended up with staining on their clothing after turning up at a newly painted food takeaway, despite warning signs being in place.
Sutherland climbed over the counter and attacked owner Brahim Hamouda at Kopas Takeaway in Tranent, East Lothian.
Mr Hamouda ran from the premises and 59-year-old delivery driver Mr Auld, who had been outside, went in to his aid.
Unemployed Archibald, 37, and Sutherland, 31, turned on the older man, punching him and pinning him against walls before kicking him to the head and body and striking his head against a window.
A judge told the pair at the High Court in Edinburgh that he accepted they did not intend to kill Mr Auld.
However, he said: "This was a completely unjustified and wholly deplorable episode of violence."
Lord Uist jailed Sutherland for six years and told him: "You bear a heavy responsibility for what happened that day, as you were the prime mover in the violence by attacking Mr Hamouda."
He sentenced Archibald to five years and three months imprisonment.
Archibald, of Musselburgh, and Sutherland, of Wallyford, both East Lothian, were originally charged with murder following the assault on March 4 last year, but the Crown accepted their guilty pleas to the charge of culpable homicide.