NEDs don't handle operational issues directly. That's not their...

NEDs don't handle operational issues directly. That's not their role.
They provide advice and oversight to management - to the tune of a few hours per week at most.

It's more likely that on review of the books, and the operation they saw the issues - or saw the money drain going on at Morilla SA and brought it to the attention of our lumbering fools sitting in Perth doing not much more than long lunches and PR/IR videos. They immediately saw the project was about to crash and thus resigned saving us the expense, and themselves the stain on their resumes. And yes, we can't blame them.

Alternatively the issues came to light coincidently just after they were appointed - they saw the company as a bad career move, and thus left.

It's terrible as shareholders we cannot question them on it. About the only way we'd find out is if a legal firm deposed them re legal action aimed at our BOD and management team - which even now remains very unlikely.