The idea that this was a deliberate act is unlikely in the extreme. The old Russian satellite died well over 10 years ago. Since it was dead, there was no way it could be controlled, so how could it possibly be blamed for causing the collision? Unless someone wants to argue it was a sleeper satellite.
In terms of timing, this would require millisecond accuracy to cause an impact. Had either satellite arrived at the impact location even a millisecond early or late, they would've missed each other by several meters. That's a level of accuracy that's extremely hard to achieve.
In terms of producing debris, this impact was about as bad as you can get. The energy involved was amazing. It might take weeks or even months to catalog all of the pieces. I don't see any rational reason for a nation as large as Russia to screw up their own badly needed communication satellites with junk in space.