The problem is of course that the amounts of money involved would put this into the small claims court.
Consumer law is fairly clear on the fact that if the consumer doesn't get what they paid for & it is not their fault then they don't pay.
It really revolves around the definition of a training flight (remember that the law tends to weigh on the side of the consumer rather than the profit making organisation) & whether any restrictions (such as standards attained) were communicated to and accepted by the consumer prior to delivery of the service.
This isn't really about flying - I agree that the flying community needs to do all it can to keep safety standards high - this is purely about whether you got what you thought you were paying for.
This could of course all be catered for by amending the booking T's & C's to allow FI discretion on sign off.
Alternatively, ending the flight before the hour is up is possible (as you say SAS, you know pretty early on whether you're with a pilot or future Darwin award nominee).
Regards, enq.