If you don't trust the official media, even independent blogs whom don't typically side with the government don't report on him favorably - eg. http://mothership.sg/2015/07/this-was-how-senior-counsel-dav...
If you don't trust the official media, even independent blogs whom don't typically side with the government don't report on him favorably - eg. http://mothership.sg/2015/07/this-was-how-senior-counsel-dav...
I think you're right that politicians in the West generally refrain from doing so not least because they're concerned about looking ridiculous or overbearing. Legally they can though, and more minor politicians often do if the claim is sufficiently incendiary and well publicised.
Here's a British member of the House of Lords suing a politician's wife simply for implying something over Twitter http://www.independent.co.uk/news/uk/crime/lord-mcalpine-lib... And the UK of course also has a fine tradition of MPs losing their libel lawsuits and sometimes even ending up in jail for perjury as a result of the original claims turning out to be largely true.
That Lee did this speaks to the general culture of Singapore why one-family-rule there needs to end and more trust in the citizens is needed to handle journalism independently.
In general, if you're not familiar and comfortable with the grammatical rules around pronoun case, don't use 'whom' at all, and stick with the more common pronouns whose correct usage you'll have learned by osmosis.