BUG in HINGE constraint?

I created a Hinge rigid_body_constraint between two geometries.
I see the constraint empty, I select it, and in the Physics tab I see a correct “Hinge” rigid body constraint.

bpy.data.objects[constraintemptyname].rigid_body_constraint.type is ‘HINGE’
returns False.

How can that be??
(Blender 2.71)

When you call this as an bge script then this is not a bug.
First of all bpy (Blender Python) is not meant to work with the bge (Blender game engine). You have to use the bge API (game engine modules, some standalone modules also working with the bge).

Also that is not implemented in the bge API (no python wrapper will be generate for it). So you can’t get constraints that are setuped in Blender.
You need to setup the constrains with python then you can get your setup values back.