[Al Skierkiewicz]

Interesting discussion so far.
The Victors have internal surge protection (MOVs) so that spikes generated in the motors will not come back and eat the FETs in the output bridge. With the Victors powered and in the coast mode with no output (PWM 127), there is effectively no connection to the Victor and as such the open circuit voltage at the motor can have spikes of up to 100 volts. (These are very short duration and are sqaushed by the protection internal to the Victor.) Unlike the backdriving when the robot is turned off, no current flows through the Victor in Coast (all FETs are off). When no power is applied to the robot, the "bridge" circuitry in the Victor can become biased on when pushing the robot around on the floor and this is the LED illumination you see during this condition. If you wire your Victor fans directly to the power input of the Victor you may also get the fans moving during this time.
Remember that when the Victor is sending a PWM signal to the motor, it is like turning a switch on and off. During the "off" period there is considerable noise and voltage generated by the motor.