Tony Virasami was caught on CCTV as he punched the wrong man after his girlfriend was accused of queue jumping
A woman has been found guilty of manslaughter after a shopper was killed following a row over queue jumping.
Antonette Richardson called boyfriend Tony Virasami to Sainsbury's in Merton, south London, but he punched the wrong man, who suffered a fatal brain injury.
Virasami, 38, admitted the manslaughter of Kevin Tripp, 57. Richardson, 37, had denied the charge.
Mr Tripp's family said the pair had shown no remorse at Southwark Crown Court and could never be forgiven.
Richardson, of Sedgehill Road, Catford, had been accused of pushing in front of shopper Adam Prendergast, as she went to buy a packet of cigarettes.
She phoned Virasami who was waiting in a car nearby, and when he came into the store she pointed out Mr Prendergast.
However, Virasami mistook Mr Tripp for the person who shouted at his girlfriend, and punched him, the court heard.
The jury saw CCTV footage of the unprovoked attack in June 2008, with the last shot capturing the fatally injured man's feet at the bottom of the frame.
Michael Worsley QC, prosecuting, said Virasami landed "the most almighty blow" on the victim, causing him to fall over and bang his head hard on the floor.
Richardson, who is a grandmother, told the court she was shocked and disgusted when her boyfriend hit the wrong person.
Mr Tripp, from Colliers Wood in south-west London - an ME sufferer who had a five-year-old daughter - died shortly afterwards in hospital.
In a statement Mr Tripp's partner Josie James said: "That he was able to be such a strong and supportive partner, father and brother despite being affected by ME is testament to his character.
"One of the last images my Rianna and I have of Kev is in the hospital on apparatus to keep him alive, bruised, yellow and so very, very cold.
Both Richardson and Virasami had previous convictions
"I had to explain to our five-year-old daughter... She talks about daddy having all the wires in him."
In a statement Mr Tripp's sisters Gillian, Laurel and Joan and brother Derek said he was a "wonderful brother".
"We do not understand how someone would get so angry over something like queue jumping that they can hit someone and cause their death.
"That neither has shown signs of remorse in court, even smiling at us during a previous hearing, makes it even harder to deal with and means we can never forgive them."
The jury took more than seven hours to deliver the 11-1 majority verdict.
Judge Geoffrey Rivlin QC said: "This is a serious case. Bail will be refused."
At the time of the attack Virasami was on bail, tagged and under curfew for shoplifting, while Richardson has previous convictions for deception and handling stolen goods, the court heard.
Both will be sentenced at a later date.