[Al Skierkiewicz]

When you push a robot, the motors begin to act like a generator. The speed controllers (both Victors and Jaguars) use power FETs that have a diode internal to the devices. As you generate current in the motors, that current forward biases the diodes in the FETs and since they are in a bridge configuration, power is back fed to the electrical system. There is no way you can generate enough current to back feed a full 12 volts to the system, but you can generate enough to light some LEDs and make it look like you have an electrical problem. All of this is normal.