A HIGH Court judge who overturned a conviction for criminal intimidation lashed out at the Urban Services Department for wasting the court's time. He was dealing with an appeal by a shopkeeper accused of threatening one of the department's officers. 'It's about time that the urban services . . . recognised that you have a problem which you must resolve and stop wasting the court's time,' Mr Justice Duffy said. Ng Wai-kuen, 34, was convicted last April of obstructing an officer and criminal intimidation. When the officer, Tang Man-fai, began seizing boxes of dried fish from the pavement outside his shop, Mr Ng was said to have threatened him. Mr Ng allegedly said: 'Bespectacled guy . . . you might be wearing a uniform now, but when you are off-duty, after you have changed out of your uniform, I will assault you.' Mr Ng was also alleged to have pushed Mr Tang. But the officer's failure to produce written proof he was authorised to arrest offenders and seize goods forced Mr Justice Duffy to acquit the shopkeeper 'on technical grounds'. A 1987 High Court ruling requires the department's officers to provide the court with the necessary documents, defence lawyer Andrew Macrae said. The judge said it was extraordinary that since 1987 the department had been 'carrying along as though the judgment doesn't exist'. Yesterday's acquittal erased Mr Ng's $2,000 fine and $2,000 costs. On April 10, the shopkeeper displayed 10 boxes outside his Bonham Road shop. Mr Tang and three other officers felt the seafood was obstructing the busy thoroughfare.