If you're on windows the following file is where the maya log handling
stuff gets setup. Should be in a fairly similar place on other OSs
C:\Program Files\Autodesk\Maya2014\Python\Lib\site-packages\maya\utils.py
That should hopefully give you a starting point for how they're hooking
into stdout
So that actually got me looking in the right area! Thanks Robert.
Here's the solution:
Since I was overwriting XStream and redefining stdout I needed to reset
stdout to point to Maya's output, but where is that? Well, the hint was
staring me in the face, I just needed to find it; the answer was i