You further need to verify that transactions have valid signatures (for which all the necessary inputs are, again, visible), which is finally exactly the same thing you need to do (but with slightly different mathematical equations) with every other cryptocurrency.
This is just technological B.S. that nobody monetary user is interested in or needs to know. It is not a financial audit.
I already described what an "audit is" and it is not something that cryptonote supports because the relevant information is obscured. The originating address is obscured, the destination addresses are obscured, even the balance itself is obscured - that is the whole *point* of the cryptonote technology which is why I say it's relevant for bookkeeping or record keeping of a trusted party-backed currency but not for defining a new form of base money.
http://dilbert.com/series/66