The fault lies with the PM for not nipping the CPF issue in the bud. It is not a new issue, and this PM has the habit of letting issues fester instead of dealing with them upfront and the moment they appear. This is the diff between father and son.
The PM can sue as that is his prerogative, but Roy's case can also be a teachable moment. The PM can stay his hand and still rip apart Roy's arguments in public; or choose to whack a fly with a sledgehammer and see his support slide further.
I mean, you can bankrupt the guy and others like him, but are you going to address the root issue or continue to keep mum? Is the govt courting libellous attacks deliberately to take them out? These are different things.
Roy is young and imho, I shall attribute his actions to misguided exuberance of youth. There is a difference between making smart satirical biting comments which are based on facts and casting loose and unmoderated remarks that expose one to defamation suits.