Would the crime be discovered had not a plumber 'kapo'
'busybody' 'do-something most of us would not bother to do' if he
had not seen the gold tap? I think sometimes, it takes a non-Kia
Su, non-KiaSi, Righteous minded, Responsible citizen to Blow that
whistle. I think he also non-KiaSai since he went to use the
toilet. 
Many people are laize faire when it comes to doing things that are
not monetarily benefitial to them or it does not affect their
family.
That plumber, tho just a plumber did what he thought is morally
right . He spoke on behalf of the people, risked law suits and his
business/job and went to complain a titan.
without this Righteous-spirited man, how long more and how much
more will the people be cheated? No one knows. Put it this way, can
anyone in this world dare to step up and assure that there are no
cases of corruption, even large-amount corruptions, that are never
caught? HP says anything is possible. I buy that. I think there are
bound to be cases of huge corruptions that also went uncovered.
Maybe many many years ago. Maybe. No one can say there is
non.