Indonesia wants the Extradition Treaty to be back dated by 15 years. This means that anything in the past can catch up with anyone. It is the same kind of thinking that destroyed Malaysia's credibility when they introduced new property ownership laws retroactively.
If Singapore will to do so, it will create huge upheaval to our legal systems. This is a precedent that it cannot oblige. It is something that is too crucial to attempt.
Shouldn't even think of it.