Seem like the 2 months behind bars make no difference at all. To silence this loser for good is to give him lashes on the butt, like what happened to Michael Fay. This for sure will work, as Michael Fay could then meet up with this Nair in US and go into obscurity.
What would you posters do if you were in Gopalan Nair's shoes? Would you shoot yourself in the foot by not apologising, thereby prolonging your prison sentence? I suspect almost all of us would do the practical thing by apologising & appearing remorseful, to obtain an early release. After reaching the safety of the U.S., I suspect almost everyone of us would then go public about any perceived injustice at the way we were treated or imprisoned. Come on! Be truthful & shame the devil!
If the Singapore Government still wants to get him, they could apply to sue in the US courts.
Of course, the US rules defamation and contempt differently, where the aggrieved party has to prove it's not what the other person said. Don't think the Singaporean govt wants to play according to American rules.