When importing FBX animations, the "Average Velocity" reported by unity in the inspector is wrong. Why?

Problem: 1.Animator creates run animation moving 7m/s in maya moving straight ahead to infinity. 2.Exports to FBX. 3.Double check exported fbx file -> correct velocity. 4.Import into Unity, in the inspector Unity tells me the animation has a non-zero velocity in the x direction and 8.302 m/s in Z 5. After zeroing out the X motion with the offset in the inspector. putting it the game in an empty scene with the character starting at the origin, the character moves the distance expected by the animator, not what unity says.

I the Average velocity just wrong? Unreliable? Based on the wrong joint?