The whole system is about self compliance. A manufacturer has to build an aircraft to a set of standards and then the manufacturer needs to sign off that there aircraft meets or exceeds the said standards.
Generally, aircraft that are questionable are audited by different CAA's very quickly after they hit the market or when they have a couple of 'similar' incidents. I don't know how many aircraft CASA have audited and I know the FAA had done dozens in the category around the globe.
World CAA's are generally very happy with how self compliance works and now they are accepting the same system for part 23 aircraft where now a manufacturer can claim self compliance based on a similar set of standards.
If an aircraft manufacturer states compliance of an aircraft does not meet that standard then they are solely 100% responsible. This way grieving widow's and their lawyers go chasing the manufacturer who has stated their aircraft is compliant and meets a standard rather than chasing a CAA who accepted the aircraft based on their own, sometimes limited, testing and evaluation.
This is a system that allows aircraft to come her market much faster than would normally happen in a fully certified system which in turn makes the cost of aircraft cheaper.
If a manufacturer cheats the system and doesn't meet the approved and accepted standards then they deserve whatever they get.
This is not an RA-Aus issue, not an FAA issue, or a CASA issue because self certification is the way the industry has been instructed to proceed into the future of aviation, like it or not.