I am also seeing playback issues even with the older DCS modules. I had a dog fight with a Su-27, I am in an F/A18-C, and in the real flight he clips me with his gun and I then go on to kill him with a Aim-9x. When I watched the playback immediately after it showed all this as I remembered it (great I thought). A couple of days later when I came to make a video from the track the Su-27 kills me every time with its guns.
It seems odd that the even the reply changes over time, I can only assume that there are some random elements in the simulation that are not stored in the track file and so generate a different out come when you replay, maybe after restarting DCS.
I can't wait until they fix this, hopefully with the proposed changes coming to support then Dynamic missions, saves and playback.