[fox46]

I expect there is back EMF protection built into the controllers which protects the controller when you cease applying power to a motor and the motor turns into a generator, backfeeding into the controller. If the controller was in brake mode it would have shorted the connection and could have damaged the brake mode functionality of the controller. Otherwise I would expect them to be equipped with some sort of supressors or diodes which (bearing in mind I have no clue how they are wired) could have fed back to the power input terminals? I would tend to think if the controllers work fine and they don't smell like magic smoke, you should be fine. I have seen many teams pushing their robots around while powered down and have watched various lights light up and fans spin from the current being generated and fed backwards through the controllers by the spinning motors.