The mother of a western Sydney man allegedly murdered over a pair of fake wireless earphones was packing for a family holiday when her son left the house for the last time.
Ross Houllis, 28, was bashed on Valentine's Day 2020 before dying in hospital three days later.
Abdul Karaali has pleaded not guilty to murder, denying involvement in the attack preceding Mr Houllis' death.
CCTV footage played to the jury on Wednesday afternoon will form a contentious part of Karaali's trial.
His barrister Irving Wallach said the Crown will not be able to prove its circumstantial case that the man allegedly seen high-kicking Mr Houllis before stomping on his head and chest is Karaali.
"What you are being presented with are clearly poor quality images," he said.
"The prosecution's evidence on its whole is of poor quality."
Janet Houllis watched from the court's upper gallery, wiping tears during the footage of her son being attacked.
Ms Houllis earlier told the court she was packing for a family trip to Hawaii when her son left their house at Wakeley in Sydney's west to sell a pair of wireless earphones shortly after 9pm on February 14, 2020.
Mr Houllis and his younger brother Matthew had been selling earphones through Facebook Marketplace for some months, and were down to their last two pairs, Ms Houllis said.
Matthew Houllis told the court he was at the gym when his brother called.
"He was just asking me if he should go and where he should meet them, either IGA or at our house," he said.
When Ms Houllis' daughter arrived home about 10pm her mother asked if she had seen Ross.
"She said 'no', and then we started to hear sirens so I ran out the door," she said.
She recognised her son's shoes on a man being loaded into an ambulance.
CCTV footage played in court showed Mr Houllis selling earphones to another man named Sami Hamdach the previous day.
Crown prosecutor Philip Hogan told the jury the Facebook account belonging to Hamdach's de facto partner messaged shortly after the transaction to ask if they were still for sale.
"She was not interested in buying a set of AirPods," Mr Hogan said on Wednesday.
"Ross Houllis was being set up, as part of a plan so Sami Hamdach could get revenge on him for selling him a fake pair.
"At some point after that, (Karaali) joined in that plan."
Text messages later recovered by police and tendered at trial showed Mr Houllis arranging to sell Hamdach's partner AirPods the next morning.
"Is it possible tonight," the response asked.
"Absolutely," Mr Houllis wrote back at 8.30pm.
"Make sure there are no cameras that see your plate number," an iMessage to Hamdach about 47 minutes later said.
"However, in fact there were CCTV cameras," Mr Hogan said.
Along with the CCTV, which Karaali denies appearing on, evidence of his phone connecting to cell towers would be presented to place him in the general area.
Mr Wallach said the connections to particular towers were not straightforward evidence.
"Phones connecting to particular call towers don't assist you in any particular way in placing the phone," he told the jury.
A DNA profile matching Karaali was also found inside a ute filmed on the same street Mr Houllis was bashed, Mr Hogan said.
During a search of Karaali's house, a mobile phone was found above a cupboard, missing its SIM card, and had been used to search for information about the incident in the days after it occurred, Mr Hogan said.
