Murray Cod
Charter Member 2011
Closely watching the performance just prior to the game booting out it looks like an accumulating memory leak. I tried lowering the scenery detail a couple of times, and sure enough I can play through to the objective. So, it's either some ground object in that part of the map that get's suppressed in the lower detail settings, or the fact that there is less of everything so the memory leak takes longer.
I will give that a try and report back (hopefully) tomorrow