> wanted to charge Harding and Reay with manslaughter
Exactly: certifications were irrelevant and toothless. Unfortunately so were the laws.
Similarly in the UK no individuals or engineers have been formally charged or convicted for any offenses relating to the Grenfell Tower fire. The causes were distributed more widely in that situation.
We need heavy criminal penalties for managers and other responsible people that are irresponsible.
And the corporations should not be able to hide behind limited liability. Additionally I suspect NZ lacks a good legal framework for chasing civil liabilities.
The bigger pattern is that organisations have systemic safety flaws, so instead they want to blame their frontline staff: pilots, teachers, engineers. Every time.
If the strongest incentives result in unsafe decisions, then the incentive to not sign-off will fail (because it won't trump the other incentives).
And professional indemnity insurance undermines some negative incentives.
Certificates are for the patsies. And certifications don't work across borders.
The consequences of criminal decisions are not nearly as bad as they should be.
Basically, within NZ certifications just don't seem to have the effects we imagine they should. Unfortunately the fix should be criminal negligence laws, but they seem to fail for other less obvious reasons some of which you mention (my further guess is that negligence would tar too many people involved including politicians, so every incidental person is keen to avoid doing the right thing).
Idealists believe in civil certifications. Realists believe in a criminal code.
Criminal negligence laws should also be able to deal with deadly software (although perhaps Facebook is too nebulous).