Brushed motor BEMF ringing
Unfortunately the reverse diodes inside the chip cause the stored inductive energy to take quite a long time to deplete. If "somehow" these diodes could be removed and replaced with a medium value resistor, the decay would be faster because energy would be burnt more quickly. 

Adding a load resistor will lower the rate at which energy can be burnt - remember you are talking about the motor current wanting to remain constant when power is removed and a higher value resistor burns that energy off more quickly BUT the diodes cannot be removed and so this looks an impossibility.