The Big Four really like back-dating things to help their clients. But lying is difficult because the facts come with built-in consistency. Mother Nature ensures all her arithmetic lines up properly every single time like clockwork, but when you try to make stuff up you have to do all that work and not make any mistakes.

And so it's actually easier to spot this fraud than to conduct it. What you need is people willing to go look and people willing to prosecute it even though that's uncomfortable because these crooks always have powerful friends.

Ultimately the bigger problem is the Big Four themselves. They are obviously Too Big To Fail and three of them are based in a single place, London. I believe that the Paris MOU provides us a model for how to fix this in the medium term but I've seen no political will to even look at the problem, much less address it.