When your ignition relay contacts open, the path of least resistance is going to be the small air gap created when the contacts first open, nothing to do with charging the .22uF capacitor. If the points are closed (good chance), then there is just the coil and power to it in the circuit. The connnection is made from coil to ground through the closed points leaving the shorted capacitor totally OUT of the equation. The same reason points degrade, only WORSE! Additionally, the capacitor only reduces the arcing for points, it does not ELIMINATE it, that's why points arc, and eventually wear out too. The points capacitor has nothing to do with switching power (black/white wire) off to the coil circuit. If your points are open when you shut off the relay (less chance), you're good to go, no arc. More studying, less guessing.