Are you guys talking about the Surface or WPF version? I assume Surface based upon the wording of your question. Is this occurring on the Surface device or the simulator, or both?
There is inertia on the pan and zoom movements (just like the regular browser version) so if you fling or zoom very quickly the control will start with a lot of inertia.
If you want to change the inertia constants for your own tastes, they are defined in SurfaceVEMap.cs in the manipulationProcessor_Affine2DManipulationCompleted function.
There's no method to reset movement, but you should be able to just touch the globe and it will stop.