Not necessarily. The threshold for audit depends on what percentage of the charity’s revenue is from the government.
As far as I can see "charity" in this context is a bit of a red herring. The C&AG's responsibility for the audit of semi-state bodies does not depend on whether or not they are charitable, or are registered as charities.
I wasn't aware that the C&AG's responsibility for semi-states/quangos was subject to a threshhold. Do you happen to know what the threshhold is?
(At a guess, the threshhold will depend on the amount of public money an agency receives, rather than on the agency's overall budget or size.)
The Auditor General cannot be everywhere at the same time. Issues can and do go on for years before the AG discovers them. And then there are those never discovered.
The C&AG is an agency, not a single person. There's about 180-200 full-time equivalent posts in the office.
Yes, the C&AG can't be omniscient or perfect. The same, obviously, is true of private sector auditors. But I think the C&AG process is more robust, or at least more extensive, that the audit process that a private company is required to go through. In addition to the standard financial audit (which seeks to answer the question "Do the accounts show a true and fair view of the income, expenditure and financial position of the body being audited?"), the C&AG can conduct value-for-money examinations of an agency (economy and efficiency of operations, adequacy of management systems, etc) and can report to the Oireachtas on "any general matters arising" from an audit or an examination.
(Private sector sector auditors and consultants can of course also conduct value-for-money examinations of a company, but will only do so if asked to by the company itself. The C&AG can act on his own initiative, or at the direction of the Oireachtas.)