It really depends on the camera (and I don't know how the XR2 works).
Many of the later-model (mid-'70s and beyond) consumer-oriented cameras had a slip clutch on the winder mechanism to deal with those instances where the user "knew" that their cartridge had more exposures than the camera said there were. There was usually a little bit of extra force required to overcome it, but allowing the slip made more sense than either letting the winder mechanism self-destruct or chewing up the sprockets to the point where rewinding the film might become impossible. (Cameras that were designed to accept a motor drive or winder usually didn't have a slip clutch; they relied on the degree of force required with a fixed mechanism to stop the winder/drive.)
If that is the case, you'll likely have twenty-five or twenty-six clean exposures and one frame with multiple exposures (probably out of register). As for damage to the camera, the next roll of film will tell—if this "safety valve" has been used often enough over the life of the camera, there may be little to tell in terms of the winding force, but as long as the mechanism can advance the film eight sprocket holes before enabling the shutter release (even if that takes more than one full pump of the winding lever), you should be okay.