Actually, it looks like a failure with the bolts connecting the front right breaking system and therefor wheel. You can see in this picture, the entire rotor is still inside the tire and the wheel itself is completely undamaged - that usually doesn't happen. If it was pushed out in the collision, there should be at least some deformation of the back of the wheel well but that's undamaged as well as the wheel which leads me to believe that it wasn't very attached at the moment of collision.
