A judge yesterday cleared a pet shop owner of chopping three men who helped an irate woman demand a refund on a cat. District Court Deputy Judge Mary Yuen Lai-wah criticised the police, saying there had been 'no proper investigation'. She told the court no photographs had been taken at the scene and no attempt made to find whether any blood was present. The judge said no forensic evidence had been produced to help determine whether the blows were defensive or offensive. Li Kwok-wai, 39, was acquitted of three charges of causing grievous bodily harm with intent on three men who had accompanied the unhappy customer to his store. Prosecutor Peter Lavac said boutique owner Cheng Chui-ping bought a golden-furred cat for $7,800 from Mr Li's shop in Tung Choi Street, Mongkok, on March 7. Ms Cheng said the animal became sick after a few days and she exchanged it for a cheaper but 'bigger and fatter' cat. But the same problem developed. On April 14, she returned to the pet shop with the three men but said Mr Li refused a further exchange or refund. After Ms Cheng went out of the shop, she claimed her friends were attacked by Mr Li with a chopper. But defence barrister Alexander King said Mr Li used the chopper in self-defence when attacked by six people claiming to be gang members. The police have laid assault charges against the three alleged victims.