If you click through to the IBJ investigation it states the backdating ran from 1999 to 2013. I don't know why the BBC only reported up to 2005.

I believe that almost zero wealth centers are scandal-free, and that some people collect the info badly, others do it very well, and there is an economy based on that alone. Enforcement is selective, intermediaries are constantly paid by various means, and time is on the side of many involved.

Picking on particular scandal to publicize is more like picking from large heaps of content in a collection, not anything unique or unusual at all.. just not widely known for real reasons...

Tax evasion is a game played by 100% of sophisticated players, to start IMHO