A MAN charged with wounding a police officer went free from court yesterday after the judge questioned the policeman's testimony. Constable Chen Siu-chen told the District Court that Lo Kwok-hung, 20, smashed a pane of glass over his head while the youth's father, Lo Kang-sum, attacked him with a knife. But Judge Surman said the policeman's wounds did not match his story as he had only suffered a small cut to his finger. The judge said the accused's medical reports showed he had suffered a fractured breastbone, an injury consistent with his claim that he had been kneed in the chest. Mr Lo Kwok-hung was acquitted of wounding with intent to cause bodily harm and resisting arrest. Lo Kang-sum, 45, also charged with wounding with intent, was found guilty of the lesser charge of simple wounding and jailed for six months. The father and son have lodged a report with the Complaints Against Police Office. The court heard the pair got into a fight with Constable Chen when he arrived at their flat on March 31 last year to arrest the son for non-payment of a $3,000 fine. 'The son claims the police officer came to their flat and woke him up when he was sleeping on the balcony by throwing a stool at him,' Judge Surman said. 'He said the police officer kneed him in the chest and punched him. He claims he did not hit the officer or attack him with glass fragments and only when he shouted for help did his father arrive.' The son's medical report and X-rays taken a few hours later showed he had a fractured breastbone. Judge Surman said it was 'a serious injury consistent with kneeing or hitting'. The judge said there was not enough evidence to prove the son was involved in the wounding of the officer and that he was 'simply unhappy' about the resisting arrest charge. The judge said he 'went over the medical reports with a fine toothed-comb' before arriving at his judgment. 'The father had a knife and there was a struggle and a tiny wound to the officer was caused by the knife,' he said.