The defeat devices were designed to detect dyno conditions and reduce emissions, it wasn't a case of a regulator trusting a computer output. They were uncovered by doing road tests.

Which a competent regulator would surely be doing randomly across the industry no?

If all they are doing is trusting what the regulated folks are saying they are doing, that isn’t what I would call effective regulation.

Most regulators don’t verify much, (the SEC almost never actually looks at bank account balances,) they just look for inconsistencies in the information they receive.

The SEC isn’t regulating banks generally so bank account balances shouldn’t matter much - they are regulating security markets no?

So looking at discrepancies between data from market participants IS verifying and regulating.

Same as if the FDA looked at raw study data and compared it to equivalent studies for similar types of drugs/treatments, or the FAA had an engineer on staff to double check elements of a new design from a major manufacturer for plausibility

I meant to imply that the SEC could check companies' bank accounts to verify the truthfulness of balance sheets and income statements.

True, though with the way GAAP and accrual accounting works (generally cash balances are only tangential to income, expenses, or even assets once you get past small to medium businesses), and the scale and number of accounts most businesses have, that’s a lot of work for a very muddied view of what is likely happening outside of some specific circumstances like a depository, clearing house, or the like.

That I somewhat like counting the number of bolts ordered and delivered by Boeing to ensure they are staying compliant with building their airframes.

If they never order any, or there aren’t many arriving where you expect, is that a problem? Sure, though it’s probably a subcontractor ordering them, or they haven’t bought any when you were looking because they have a large stockpile, or whatever.