ClosedCurveOrientation is different or Rhino5 and Rhino6

What was the reason to change Curve method ClosedCurveOrientation between Rhino 5 and Rhino 6?

I have the same curve on both Rhino 5 and Rhino6.
Rhino5 returns Clockwise string and Rhino 6 CounterClockwise string

Ok it seems in Rhino5 there was a small bug giving opposite string output.