A magistrate did not require expert evidence to conclude that the penis was one of the most sensitive parts of the male anatomy, a judge ruled yesterday. The decision by Mr Recorder Wong Ching-yue put an end to one of four points raised by lawyer Peter Cosgrove on behalf of jade worker Chang Kam-tong, 30. Chang was convicted on May 24 of indecently assaulting a woman on the MTR and sentenced to two weeks' jail. He lost his appeal against conviction in the Court of First Instance yesterday. Mr Cosgrove argued Magistrate Adriana Ching erred in concluding his client must have noticed he bumped into the female passenger three times while travelling on the train on March 10. 'The magistrate took the view that 'the penis is one of the most sensitive areas of the male anatomy. He [Chang] could not have failed to notice the contact with his penis when there were three bumps.' 'The sensitivity of a penis as opposed to any other part of the body is a matter of expert evidence, and there was no such evidence before the court,' Mr Cosgrove said. Chang was arrested after two police officers noticed his movements when the train travelled from Tsim Sha Tsui to Jordan at about 7pm. In convicting Chang, the magistrate accepted there were discrepancies in the case against him and concluded one of the two police officers had exaggerated his account. Mr Cosgrove argued the victim's evidence was inconsistent and said the exaggeration by a police officer tainted the whole evidence and made the conviction unsafe. Mr Recorder Wong dismissed the points, saying the magistrate was right to treat the other officer's evidence independently. 'As to expert evidence on the sensitivity of the penis, it isn't required for such a matter. Normally expert evidence would only be required when the court had difficulty understanding or assessing evidence in respect of matters which are not commonly known. 'The sensitivity of the penis is not such a subject.'