Control Problems?
Looks like a control problem-not hot dogging. Something like a control lock or aft c.g, or control system FOD.
Once the crew recognized the uncontrollable pitch up, seems like they did a pretty good job by rolling to the nearest horizon and letting the nose fall, but they were not quite able to roll back to wings level before intersecting the ground. Their sink rate was nearly stopped, and that must account for the relatively low fatality count.
I was not able to get the Russian link to open, so I do not have the local comment that probably is more specific as to cause.
The two fatalities are a sad reminder of the inherent dangers in aviation. R.I.P.