I just checked my Pacemaker speed... The shutter curtain on it when set to a similar tension also bounces slightly, however, it seems like it is wound far enough into the body by the time the travel stops that when it bounces it avoids exposing any film.
I also discovered something interesting... With the rotating back set at a 45* angle, i can see a little bit into the bottom of the camera. When the curtain ceases it's travel, it is not far traveled into the camera body at all. In fact, it's travel stops at the free spinning roller inside the back. When it comes to a stop, it bounces, exposing the film. However, when it has come to rest and finished bouncing it has returned to its original position with the metal lip of the shutter opening resting on the metal roller. But then, when you bring the mirror back down again, the shutter drops into the camera to the point where the metal lip is much further below the roller.
However, even when it is set so that the natural resting place is where the metal lip is below the roller, by winding it by hand and releasing it, it still bounces up above the roller and to the point where it would re-expose the film.