A judge's blunder cost a teenage convict three months of freedom, the Court of Appeal heard yesterday. Kong To, 19, will now have to start his wounding sentence from scratch after a District Court judge illegally sent him to a detention centre, flouting the wishes of the Commissioner for Correctional Services. 'This man has spent time in custody already and in the wrong place,' Mr Justice Kemal Bokhary said. 'A memorandum from the Commissioner said he considered Kong unsuitable for . . . a detention centre. The result is indeed one which is not authorised by law.' He noted that the Commissioner had concluded that a training centre sentence would be appropriate. But District Court Judge Fergal Sweeney ignored the recommendation. The Attorney-General brought the appeal after the error was discovered. The Court of Appeal yesterday concluded that the decision was 'unauthorised by law' and sent Kong to a training centre instead. The length of terms served at detention centres and training centres is based on performance. Centre staff decide when to release inmates, not the courts. 'There is no provision to deduct the time spent in the detention centre from the training centre time,' Mr Justice Bokhary said. Kong yesterday told the Court of Appeal he wanted to go to prison to serve a finite term. That way his three months in detention could work to his credit. But the court rejected his request. 'The events that happened have troubled us but at the end of the day we see our duty to society and indeed to this young man to be clear,' Mr Justice Bokhary said. Kong was convicted of leading a gang attack, at the age of 17, on a teenager who had teased his girlfriend. The transport worker and Wo Shing Wo triad member was found guilty in December last year of wounding. He was one of 10 men who had descended on the lone victim armed with metal pipes.