@Arella Mae,
It's a species wide practice for the mother cat to carry their kittens using that type of technique. By the back of the neck. Cats do it as well as lions.
Not sure if this binder clip is physiologically having the same effect or if the video is a fake. Maybe when the mother cat uses the hold, the kitten isn't physiologically frozen but psychologically frozen. His behavior is trained to remain still while being carried by the mother. The kitten could still squirm or fight but chooses not to because of the conditioning.
If it's real, perhaps AM, when you are holding the cat by the back of the neck, maybe you were not grabbing the correct nerve areas that the mother cat instinctively knows the location. If it isn't a physiological reaction, then the cat which you tried to grab by the back of the neck took umbrage to your actions.
Maybe the cat is a neurotic individual and the clip itself works on a rare few cats who have mommy cat issues?