The police officer cleared of killing Ian Tomlinson has been found guilty of gross misconduct by a disciplinary panel for discreditable conduct and use of force.
Pc Simon Harwood, 45, admitted that he used unnecessary force when he hit the newspaper seller with his baton and shoved him to the ground during the G20 protests near the Royal Exchange Buildings in the City of London in April 2009.
He also accepted that his actions and the way they were reported had brought discredit on the Metropolitan Police, and that this amounted to gross misconduct.
A police panel found that he had breached standards over discreditable conduct, use of force and authority, respect and courtesy, and that this should be counted as gross misconduct.
Patrick Gibbs QC, for Harwood, told the hearing the officer accepted that it was "impossible for him ever again to be employed as a police officer".
The panel, consisting of two police officers and a lay member, decided not to consider an allegation that Harwood's actions inadvertently caused or contributed to 47-year-old Mr Tomlinson's death.
Mr Tomlinson, an alcoholic who had lived rough for several years, managed to walk 75 yards after he was hit and pushed, but collapsed and later died from internal injuries.
The hearing was told that Harwood had twice offered to resign from the Met in the wake of the death, because he thought it was "the right thing to do". Mr Gibbs said: "He has described again and again the huge gap between what he understood at the time and thought he was doing at the time, and what he now realises was the case. He had no way of knowing at the time what Mr Tomlinson's level of intoxication was and all of the medical difficulties before that time."
The father of nine's widow, Julia, and his two stepsons walked out of the hearing room saying "Whitewash" as Mr Gibbs addressed the panel.
Harwood, from Carshalton in Surrey, has already been acquitted of Mr Tomlinson's manslaughter, although an inquest found the father of nine was unlawfully killed. This is the first time that a police disciplinary hearing has been held in public by the Met.