'They both got out of the taxi and he (Mr Shepherd) describes Mrs Goldsmith slapping her husband to the face, ' she said.
The court was told Mrs Goldsmith then asked the taxi driver to call the police. "He says "She appears to be unconscious, she isn't moving".
"Mrs. Goldsmith said she couldn't recall how it happened but her husband punched her in the face with a closed fist to the left side of her face", said Shilton.
After losing consciousness for around 15 seconds, Shilton said Julie-Anne Shilton became "upset, starts crying and uses some railings to assist her".
After the incident, Goldsmith was described as "panicked and walking in and out of the house, trying to get her to go back in the house". The taxi driver reportedly challenged Gary, 52, after witnessing the attack, but he became very aggressive.
Julie-Ann is his fourth wife.
At the police station, Goldsmith told officers he had pushed his wife hard with his left hand, but denied using a hook.
Goldsmith, who appeared at Westminster Magistrates' Court today, had admitted a charge of assault by beating.
After pleading guilty to one count of assault by beating, Gary, 52, has been released on bail until November 21, when he will be sentenced, reported the Evening Standard.
Chief Magistrate Emma Arbuthnot said: "I am excluding custody and looking at a community order".
When that marriage broke down he married again six years later to Luan.
She left him amid a reported row over his drug use and he later met and married Julie-Ann.
He was brought up with his sister in Southall, west London.
His father was a painter and decorator from west London and his grandfather worked as a miner in Durham.
In 2005, he sold his shares in Computer Futures for £17million and bought a villa in Ibiza and called it "La Maison de Bang Bang".