I won't comment on the guys’ decision. That really is a personal one between he and his two families. However, about the law: back in the day Straits Chinese were at the top of the heap in colonial Malaysia. Those who had converted to Christianity would frequently force their ethnic Malay servants and employees to convert at the threat of dismissal and/or beatings, often with the co-operation of the British Colonial Government. Out of context and in the current political environment the law seems like raw Islamic fundamentalism but there is often more than one side to every story.
Edit: I should say I don't think the law is right but a lttle understanding goes a long way.