Altitude intercept point drawn on curved path instead of straight path

[falcon71]

This screenshot was taken at the SID OPKC RWY 25L BADU1D:

As you can see, the altitude intercept point (FL070) was drawn on a path resembling the actual curved flight path instead of the straight path on the right. I wonder, if this is actually correct, since the A300 cannot draw a curved flight path.

On a related note, the path on the ND looks surprisingly bendy when performing a direct to...