“Compelling evidence” of what? It’s only compelling evidence that the flight time logged in a pilot’s log book matches the hirer’s charging methodology. I think you’ll find CASA’s more worried about whether the logged flight time equals the pilot’s actual flight time. (Crazy as it may seem.)
“Many practices are generally considered acceptable” by whom? I don’t doubt that there are many and varied practices out there. As I said, it just goes to show how unimportant the exact numbers are to pilot competence and airworthiness in the real world.
I remain in awe at our apparently endless ability to complicate simple concepts.