You mistake was sitting back and marveling at your handy work. If you are in a furball like that, knock him down and quickly scoot off to the next victim. In DCS the Russians have all the advantages, an off-boresight shot by a Russian heater can be nasty.
Now if it had been a 1v1, I would say taunt the guy, fly past him, dump flares in his face, and buzz the survivor in the cute.