while i am not legally trained, legal matters on the paper always attracted my attention
In Singapore, the onus is on the defendent and not the plaintiff to prove that the comment is not defamatory unlike in other countries. Defamatory is judged based on the impact and damage caused. This is the definition of defamation:
"if it tends to (i) lowers the plaintiff in the estimation of right-thinking members of society generally, or (ii) cause the plaintiff to be shunned or avoided; or (iii) expose the plaintiff to hatred, contempt or ridicule. "
The best defence against defamation will be for the defence to prove that the statement in question is factual. This is how SPH fends off NKF and counter-sue them instead. it does not matter if it hurts a person's reputation so long as it is indeed true.
Exception will be unless the comment is made with malice, which is with the intention to cause damage or controversy. Or in another case, if the statement was made recklessly without regard to whether it is true or not.
"The gravity of the statement, the standing of the plaintiff, the extent of the publication and the effect of the publication on the plaintiff are factors to be taken into consideration for ascertaining the quantum of the damages. The court also takes into account the intended deterrent effect against the defendant."
If the defamation suit succeeded, damage can be mitigated by offering an apology and an undertaking not to republish it.
As for moderator, so long as they prove that they were not negligent in the issue
Anyway, if the person is vested in that particular company, it makes no sense to make defamatory comment on it unless you want the share price to go lower so as to accumulate.
For the future, maybe the administrator want to restrict viewing right of companies to members only while keeping the other segment open to public view. In this case, damage can be mimimized by the fact of limited damage since we only have 700+ members and only a few are vested.
still better to consult a lawyer on this matter