Ferris's quote is spot on:
Why does resigning absolve you of what you have done?
The resignation letter is used in many government organisations as a way of "absolving" all the sins.
This is not so - take a close look at the Craig Thompson affair. CT is being now placed in a situation to answer for his "adduced" sins by Fair Work Australia, albeit, taking three years to investigate. A precedent and a "shiver in the boots" of all those non-compliant CEO's.
In the big world, ASIC frown upon the miscreant Director and there are substantial penalties attached.
Big salary - Big penalty when you get it wrong.
This may just explain why there are large and viscous legal departments in casa - Have not looked at ASA yet!!