59Ncm is roughly equivalent to 6kg force per cm. If the screw on your coupler creates a lever arm of about 2cm, that is about 3kgf.
So the question is, could you lift 3kg with a finger tip? I think you probably could, if briefly. So you are able to apply more torque with your finger tip than the motor is rated to produce. I really can't tell from a video what "hold it lightly" means. Your light touch may be quite different to mine 
Obviously, after the gearing provided by the final gear, the torque will be higher, so applying torque to the driving shaft may not be representative. I would try the test again with the worm gear train attached. To be honest, not really sure what this finger test shows without knowing the final torque required.