A servo does not use pwm, but rather a different timer based pulse of between 1 and 2 millisecond width in a 20 millisecond frame.
Isn't that pwm? The signal is encoded in the width of the pulse after all. There seems to be some disagreement on this point: thread.
In the end it doesn't really matter to me, since I know I can do what I need with any of the digital pins. There is still the matter of confusion in the documentation that might trip up someone else, though.