Comment #8 on issue 1097 by ryd...@gmail.com: Not all shapes support borderColor/borderWidth https://code.google.com/p/moose-technology/issues/detail?id=1097
What is indeed impossible in Athens, is drawing unscaled strokes on a scaled path, since path scaling only occurs as part of drawing, not creation.
The above avoids that by using no scaling to draw the ellipse.