RE: Where did I go wrong?
I use Futaba and Hitec servos and reverse them the same way, by reversing the red and green wires on the potentiometer and the orange and brown wires on the motor. I never had a problem doing this. You can go to the Hitech website and go to "general servo frequently asked questions" to see a diagram. I would like to upload it with this reply to share with everyone, however, it is a PDF and I cannot upload that type of file. I can PM it to you if you would like. Hope this helps.
Steve