I'm expecting (with an admitted bit of schadenfreude) a Russian production-peak attribution error caused by Putin's power grab. The re-nationalization of production is certain to cause productivity declines over the long term. It'll appear  a validation of natural course, but it'll be merely a function of political course.
Yes - it's going to be very hard for outsiders to disambiguate the two.
To be exact the production decline was expected and we may strongly suspect that Yukos was overproducing a lot. The Russian peak was already in the end of the '80s. The big fields are very mature. Nothing special here. Nationalized oil companies are not worse than the others. All those big private ones are now in decline, as posted in this blog some time ago...