As you have said, neither you nor the other guy is qualified to make a technical assesment on this and we just have to wait for yhe investigations to play out.
However, what we can assess is the ex-employee's actions and multitude of claims, which while in isolation seems benign, together makes her look more like a vengeful ex-employee than a credible victim
The thing is, the death penalties in Singapore are in the single digits per year (out of a population of 6 million, effectively higher as this excludes non-citizens). People are not killed without thought, there is careful and lengthy investigations in each and every case.
The deterrence does work and saves countless lives that would have been taken from ODs and cartel-ish activities