Hang on there a minute Schairbus.
"Under-resourced departments" is whose fault?
"Vigilance" is not the only solution. It's one of many.
"A discrete email"? No! A private, secure, but very public method of fact checking would be helpful. Why hasn't this been done, or why hasn't this picked up a problem especially after the last time?
Not blaming everyone. But there are several issues here and they appear to revolve around insufficient or inappropriate supervision.
If there were plenty of warning signs, where is the disconnect preventing the notification from reaching the appropriate people who could rectify the situation? Or was the situation just left to fester because no one felt compelled to spill the beans or were they waiting for a supervisor to fall on his/her sword?
If I were a CASA investigator, there'd be some straightforward actions as a result of the actions of a single individual. If, as you suggested, there were plenty of warning signs, I and a team of headhunters would be going through QF engineering like a dose of salts.