I know the game calls it FXAA. I also know that I've implemented FXAA many times, and whatever it is doing, it's not FXAA. No, not even a really low-quality version of FXAA. Calling it FXAA gives FXAA a bad name.
Since you seem so sure that it is (for no discernible reason other than the game's say-so) I even went through a frame in NSight, found the blur-pass, and checked its shader code. Surprise: it's not FXAA. Which of course everyone could actually see simply by looking at its output.
Now can we stop reverting the edits?