Practical suggestions. How about CAA inspections to include rigorous examination of an operation's Safety Management System, including examples of its application over the past time period? Pilots are bulletproof in any contentious discussion with owners or managers if they throw their own SMS back at them.
Satsuma, you may be expecting too much due to a misunderstanding. This was a private flight in the owner' own aircraft. What you are asking is a bit like expecting the DVLA to show up to check out your safety management system for going out in your own car, albeit you might pay a personal chauffeur to take you to a destination.