Tether breaks the laws of physics and can fling self in orbit

The example provided in the sandbox is rather.. exaggerated, but it conveys the point pretty well, I think.

Steps to reproduce:

1. Take an astronaut out on an EVA adventure
2. Go to the farthest part of the weird centrifuge thing and tether to it
3. Exit first person so as to not break the astronaut, and then switch to the main command pod and set throttle to 100
4. Switch back to the tethered astronaut and look at the map screen. If reproduced correctly you should see that its orbit is changing rather significantly.
5. Let go of the tether and you will fling yourself.

This is more extreme when in orbit of places like Luna, in which my brother nearly managed to fling himself out of the solar system.