The rotor is "per se" designed to never let this happen. The combination from the beginning to traverse all 3 switches is 1:1, so unless the reflector connects

The rotor is "per se" designed to never let this happen. The combination from the beginning to traverse all 3 switches is 1:1, so unless the reflector connects to itself, it will never actually collide. Or let's put it differently. Imagine just 1 switch, as it's the same reasoning. It will always change the letter, and will never return the same letter, given that the first switch always follows the key you are pressing.