Trying to figure out if there’s a problem with Australia↔Austria spherical linear interpolation in the World Countries example, as hinted at by Hadley Wickham.
Note how the geodesic is always a straight line under the orthographic projection, since it is always going through the centre. (Except for the initial view centred at (0°, 0°), which is not on the geodesic). This is true for all azimuthal projections.