I recently revisited some import code I have and took a look at the am.entities.add_face method. It seems that face orientation is dependent on where the face is drawn and what existing faces it connects to.
If the face is drawn free of other faces and away from any of the x, y, or z axes, it is drawn with the face normal obeying the right-hand-rule (RHR).
It would be very helpful if the Ruby API had an additional method –
that would create a face where the normal always followed the RHR.