Prior to Yong Vui Kong (blog post here), there was another drug trafficking case where the Singapore High Court exercised its discretion under legislative amendments for drug trafficking during the sentencing hearing. The decision explains the manner by which this discretion is exercised and highlights the judge’s concerns. This was in the case of Chum Tat Suan (24 October 2013).
One of the conditions that an accused convicted of drug trafficking has to meet to benefit from this judicial discretion is that he/she must be found to be a mere drug “courier”. Recognising, among others, that this issue was “a matter of life and death” for the accused, the judge decided to give the “benefit of doubt” to the accused of being a mere “courier”, though no new evidence about this was introduced at that stage and evidence earlier adduced during trial on this point was found to be “not unequivocal”.
Ps: Thanks to CHEN Siyuan and Jack LEE from the Singapore Management University for highlighting important facts about the Chum Tat Suan case
Wrongful Convictions Blog 
No, actually Chum Tat Suan was never sentenced to death. He was convicted but sentencing was adjourned for submissions, so he was only ever sentenced to life imprisonment. On the other hand, Yong Vui Kong was actually sentenced to death, and then had his sentenced reduced. So the press did get it right.