As long as the hardware is the same, the calibration LUT to the monitor should be the same. Different video cards would probably make a difference.
As for the profile itself (the icc profile describing the monitor in its calibrated state), that is the application's responsibility. The application converts from the source profile to the display profile. Windows stays completely out of the way here and does nothing, it only makes the profiles available for the apps. In Mac OS X you have this thing called ColorSync (no equivalent in Windows) that could possibly interfere and muck things up.
It could also be that the profile is simply not loaded in either OS. That happens.
In the Adobe Lightroom forum there was an issue recently, where Mavericks users complained about washed out shadows in the Develop module - not dramatic, but noticeable. It affected all calibrators, but not pre-Mavericks OS X, and not Windows. Photoshop reports were mixed and inconclusive (possibly related to GPU processing on or off). The general consensus boiled down to OS X 10.9 bug, and bug reports were sent.
Have you tried the Dell hardware calibrator? (Would require i1 Display Pro sensor however). But that should rule out the calibration LUT, since it would be loaded into the monitor and take the video card out of the equation.