There are many misdemeanors a Russian oligarch can commit with impunity, from fraud to murder, and many of them have done so. There's only one really unforgivable crime in the unwritten code of Russian laws known as 'ponatiye', or understandings, and that is defiance of the Kremlin's will.

Mikhail Gutseriyev, former chief executive of Russian oil group Russneft, committed exactly that crime last month.